Merge bitcoin/bitcoin#23979: test: wait for rather than assert presence of file in startupnotify test

96eb009 test: wait rather than assert presence of file in startupnotify test (fanquake)

Pull request description:

  Should fix #23967.

ACKs for top commit:
  brunoerg:
    crACK 96eb009
  kristapsk:
    utACK 96eb009

Tree-SHA512: 9107970e45c027cfc6c6cbfcfd5a7d9f5956259bbbb11f5b180c3947126e42e62c0f8ffd69cf7b39b51c9c5b4fedbb753839d59aebe876be68c1484bb6065819

Author: MarcoFalke

upgrade-tracking/commit-database.csv

@@ -421,3 +421,6 @@ db5f441408acbcb399e8a4bc6c645dababfcaa6c,2022-01-04,fanquake,"Merge bitcoin/bitc
 e13f8f775d9e8da04db0e072040d11237c5d1089,2021-10-15,fanquake,"build: build x86_64 Linux Boost with -fcf-protection=full",success,none,automatic,upgrade-tracking/patches/success/e13f8f775d9e8da04db0e072040d11237c5d1089.patch,Clean cherry-pick
 5a8f907c93f158c54e58706d6d8c6b0a1a3205ba,2021-10-15,fanquake,"scripts: add CONTROL_FLOW to ELF security checks",success,none,automatic,upgrade-tracking/patches/success/5a8f907c93f158c54e58706d6d8c6b0a1a3205ba.patch,Clean cherry-pick
 4ee78450fff09781d6d0e3e02a486f30428d72d2,2022-01-04,fanquake,"Merge bitcoin/bitcoin#23826: test: Make AddrMan unit tests use public interface, extend coverage",success,modified,patch-modifier,upgrade-tracking/patches/modified/4ee78450fff09781d6d0e3e02a486f30428d72d2.patch,Applied with DigiByte preservation
+b1e8f0b96edf87b0ee68e85ea50c62e459ed8cb8,2021-12-08,fanquake,"guix: use uptream nsis-x86_64",success,none,automatic,upgrade-tracking/patches/success/b1e8f0b96edf87b0ee68e85ea50c62e459ed8cb8.patch,Clean cherry-pick
+187dc1ec0c867ffcf44f607bbb928909d86a81ca,2021-12-15,fanquake,"build: use python-asn1crypto from upstream",success,none,automatic,upgrade-tracking/patches/success/187dc1ec0c867ffcf44f607bbb928909d86a81ca.patch,Clean cherry-pick
+84f9931cb44932751415f2ca48501ba01eed39a6,2021-12-30,fanquake,"guix: use upstream python-requests (2.26.0)",success,none,automatic,upgrade-tracking/patches/success/84f9931cb44932751415f2ca48501ba01eed39a6.patch,Clean cherry-pick

upgrade-tracking/last-processed.txt

@@ -1 +1 @@
-fa9f4554ca5e64e7960b74dd0ad8fb1cd7c2f091
+84f9931cb44932751415f2ca48501ba01eed39a6