chore(examples): remove wee_alloc from wasm-demo and ensure-no_std

[MegaRedHand]

Description

The wee_alloc crate is unmaintained. Even if we use it only for examples, it triggers security vulnerability warnings.

Checklist

• Linked to Github Issue
• Unit tests added
• Integration tests added.
• This change requires new documentation.
  • Documentation has been added/updated.
  • CHANGELOG has been updated.

[codecov]

Codecov Report

Merging #1337 (55f0226) into main (e1bfb73) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1337   +/-   ##
=======================================
  Coverage   97.50%   97.50%           
=======================================
  Files          92       92           
  Lines       37684    37684           
=======================================
  Hits        36745    36745           
  Misses        939      939           

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[github-actions]

Benchmark Results for unmodified programs 🚀

Command	Mean [s]	Min [s]	Max [s]	Relative
base big_factorial	3.739 ± 0.013	3.712	3.756	1.00 ± 0.01
head big_factorial	3.738 ± 0.014	3.720	3.761	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base big_fibonacci	3.236 ± 0.012	3.223	3.257	1.00
head big_fibonacci	3.250 ± 0.017	3.220	3.272	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base blake2s_integration_benchmark	9.185 ± 0.104	9.088	9.419	1.00 ± 0.02
head blake2s_integration_benchmark	9.173 ± 0.091	9.027	9.315	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base compare_arrays_200000	3.222 ± 0.017	3.202	3.256	1.00 ± 0.01
head compare_arrays_200000	3.217 ± 0.022	3.180	3.246	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base dict_integration_benchmark	2.248 ± 0.012	2.232	2.269	1.00
head dict_integration_benchmark	2.258 ± 0.012	2.241	2.275	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base field_arithmetic_get_square_benchmark	1.745 ± 0.022	1.717	1.777	1.01 ± 0.01
head field_arithmetic_get_square_benchmark	1.725 ± 0.008	1.712	1.738	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base integration_builtins	9.153 ± 0.156	9.017	9.537	1.00 ± 0.02
head integration_builtins	9.141 ± 0.102	9.060	9.368	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base keccak_integration_benchmark	9.239 ± 0.107	9.145	9.478	1.00 ± 0.02
head keccak_integration_benchmark	9.208 ± 0.131	9.106	9.454	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base linear_search	3.264 ± 0.018	3.245	3.294	1.00
head linear_search	3.273 ± 0.015	3.251	3.294	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base math_cmp_and_pow_integration_benchmark	2.339 ± 0.009	2.329	2.358	1.00
head math_cmp_and_pow_integration_benchmark	2.339 ± 0.008	2.322	2.347	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base math_integration_benchmark	2.139 ± 0.006	2.128	2.146	1.00
head math_integration_benchmark	2.144 ± 0.009	2.133	2.159	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base memory_integration_benchmark	1.875 ± 0.008	1.866	1.892	1.00
head memory_integration_benchmark	1.877 ± 0.008	1.865	1.891	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base operations_with_data_structures_benchmarks	2.143 ± 0.042	2.117	2.261	1.01 ± 0.02
head operations_with_data_structures_benchmarks	2.131 ± 0.009	2.121	2.152	1.00

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
base pedersen	827.0 ± 3.6	821.8	831.7	1.00
head pedersen	827.7 ± 3.8	823.8	835.9	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base poseidon_integration_benchmark	1.518 ± 0.007	1.512	1.533	1.00 ± 0.01
head poseidon_integration_benchmark	1.517 ± 0.004	1.512	1.523	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base secp_integration_benchmark	2.497 ± 0.007	2.486	2.511	1.00
head secp_integration_benchmark	2.503 ± 0.009	2.491	2.515	1.00 ± 0.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base set_integration_benchmark	1.278 ± 0.009	1.269	1.303	1.00
head set_integration_benchmark	1.283 ± 0.026	1.270	1.357	1.00 ± 0.02

Command	Mean [s]	Min [s]	Max [s]	Relative
base uint256_integration_benchmark	6.103 ± 0.050	6.065	6.199	1.00
head uint256_integration_benchmark	6.110 ± 0.069	6.044	6.278	1.00 ± 0.01