[fix](export) remove task from map finally(#51171)

[morningman]

bp #51171

[Thearas]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[morningman]

run buildall

[doris-robot]

TPC-H: Total hot run time: 39420 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpch-tools
Tpch sf100 test result on commit 1b2af49a3bc6e3e6e477abe4844e6764d310efa0, data reload: false

------ Round 1 ----------------------------------
q1	17598	6703	6568	6568
q2	2064	171	161	161
q3	10624	1041	1129	1041
q4	10561	773	738	738
q5	7734	2808	2746	2746
q6	213	132	129	129
q7	990	610	599	599
q8	9357	1937	1978	1937
q9	6655	6437	6430	6430
q10	7029	2228	2251	2228
q11	462	262	261	261
q12	395	210	207	207
q13	17916	2952	2993	2952
q14	250	200	200	200
q15	503	456	461	456
q16	494	398	369	369
q17	974	561	572	561
q18	7254	6545	6614	6545
q19	1399	1079	1039	1039
q20	480	203	207	203
q21	3974	3119	3180	3119
q22	1084	986	931	931
Total cold run time: 108010 ms
Total hot run time: 39420 ms

----- Round 2, with runtime_filter_mode=off -----
q1	6568	6575	6490	6490
q2	323	241	239	239
q3	2903	2742	2741	2741
q4	2047	1803	1736	1736
q5	5785	5704	5668	5668
q6	207	128	128	128
q7	2201	1805	1820	1805
q8	3340	3500	3492	3492
q9	8846	8679	8824	8679
q10	3611	3529	3478	3478
q11	615	504	500	500
q12	773	607	587	587
q13	9366	3095	3130	3095
q14	310	270	289	270
q15	511	460	477	460
q16	482	426	452	426
q17	1819	1603	1572	1572
q18	8070	7710	7729	7710
q19	1714	1541	1403	1403
q20	2108	1906	1815	1815
q21	5344	5249	5183	5183
q22	1106	1012	1023	1012
Total cold run time: 68049 ms
Total hot run time: 58489 ms

[doris-robot]

TPC-DS: Total hot run time: 196214 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpcds-tools
TPC-DS sf100 test result on commit 1b2af49a3bc6e3e6e477abe4844e6764d310efa0, data reload: false

query1	1274	888	900	888
query2	6320	1981	1907	1907
query3	10828	4274	4399	4274
query4	61233	32404	23849	23849
query5	4704	468	454	454
query6	406	174	172	172
query7	5466	320	315	315
query8	318	233	220	220
query9	8471	2581	2562	2562
query10	450	291	259	259
query11	16056	15172	15628	15172
query12	161	107	101	101
query13	1396	458	418	418
query14	9876	7658	6574	6574
query15	202	181	188	181
query16	7153	460	536	460
query17	1150	571	606	571
query18	1868	331	316	316
query19	210	160	156	156
query20	119	110	111	110
query21	207	104	108	104
query22	4773	4429	4780	4429
query23	34552	33764	34369	33764
query24	6243	2925	2934	2925
query25	569	432	442	432
query26	660	177	201	177
query27	1814	358	373	358
query28	4129	2142	2123	2123
query29	698	450	423	423
query30	240	154	152	152
query31	984	839	838	838
query32	66	55	56	55
query33	463	275	287	275
query34	914	512	520	512
query35	824	709	730	709
query36	1116	965	994	965
query37	109	69	69	69
query38	4059	3954	4015	3954
query39	1519	1476	1478	1476
query40	201	103	99	99
query41	50	48	49	48
query42	119	101	108	101
query43	543	479	475	475
query44	1154	829	812	812
query45	181	164	164	164
query46	1163	719	736	719
query47	2024	1953	1970	1953
query48	476	390	389	389
query49	733	403	381	381
query50	828	439	430	430
query51	7346	7145	7257	7145
query52	106	85	88	85
query53	264	180	180	180
query54	573	490	496	490
query55	78	82	78	78
query56	280	249	245	245
query57	1261	1173	1135	1135
query58	217	212	212	212
query59	3289	3076	3175	3076
query60	283	259	261	259
query61	110	104	146	104
query62	787	693	712	693
query63	230	188	193	188
query64	1431	678	623	623
query65	3240	3184	3186	3184
query66	681	296	293	293
query67	15851	15816	15594	15594
query68	3983	570	567	567
query69	454	267	269	267
query70	1193	1110	1076	1076
query71	351	255	244	244
query72	6408	4146	4083	4083
query73	757	343	360	343
query74	10102	8937	9061	8937
query75	3376	2630	2647	2630
query76	1880	1070	1070	1070
query77	485	270	270	270
query78	10706	9549	9468	9468
query79	2029	588	594	588
query80	1378	425	430	425
query81	523	224	223	223
query82	1244	90	87	87
query83	276	145	145	145
query84	286	82	82	82
query85	998	304	291	291
query86	391	292	292	292
query87	4401	4202	4217	4202
query88	4002	2421	2386	2386
query89	420	290	299	290
query90	1822	182	188	182
query91	183	151	148	148
query92	58	48	50	48
query93	2647	543	552	543
query94	765	288	279	279
query95	362	262	259	259
query96	622	283	279	279
query97	3348	3182	3186	3182
query98	217	202	199	199
query99	1569	1289	1275	1275
Total cold run time: 312335 ms
Total hot run time: 196214 ms

[doris-robot]

ClickBench: Total hot run time: 29.97 s

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/clickbench-tools
ClickBench test result on commit 1b2af49a3bc6e3e6e477abe4844e6764d310efa0, data reload: false

query1	0.03	0.03	0.03
query2	0.06	0.03	0.03
query3	0.23	0.07	0.06
query4	1.62	0.10	0.10
query5	0.54	0.52	0.52
query6	1.15	0.72	0.73
query7	0.02	0.02	0.02
query8	0.04	0.03	0.04
query9	0.56	0.50	0.51
query10	0.55	0.54	0.56
query11	0.14	0.10	0.11
query12	0.15	0.12	0.11
query13	0.62	0.59	0.59
query14	0.78	0.79	0.80
query15	0.85	0.82	0.82
query16	0.38	0.38	0.37
query17	1.07	1.04	0.99
query18	0.24	0.23	0.22
query19	1.98	1.86	1.84
query20	0.01	0.01	0.01
query21	15.41	0.55	0.57
query22	2.75	2.48	1.75
query23	17.08	0.91	0.73
query24	3.43	1.00	1.01
query25	0.32	0.24	0.16
query26	0.32	0.14	0.13
query27	0.04	0.04	0.05
query28	10.21	0.47	0.46
query29	12.61	3.22	3.21
query30	0.24	0.06	0.05
query31	2.86	0.40	0.39
query32	3.24	0.46	0.45
query33	2.96	3.00	3.03
query34	17.06	4.54	4.42
query35	4.52	4.53	4.48
query36	0.68	0.46	0.48
query37	0.08	0.06	0.06
query38	0.05	0.04	0.03
query39	0.03	0.03	0.02
query40	0.16	0.12	0.12
query41	0.08	0.02	0.03
query42	0.03	0.02	0.02
query43	0.04	0.03	0.03
Total cold run time: 105.22 s
Total hot run time: 29.97 s

[dataroaring]

LGTM