Add exclude elements to list of non-parallel

[munrojm]

Fixes issues with exclude_elements queries not returning correct results due to incorrect requests parallelization.

[codecov-commenter]

Codecov Report

Merging #649 (e8880bb) into main (05dd0c0) will decrease coverage by 0.49%.
The diff coverage is 25.00%.

@@            Coverage Diff             @@
##             main     #649      +/-   ##
==========================================
- Coverage   85.04%   84.55%   -0.50%     
==========================================
  Files          36       36              
  Lines        1498     1502       +4     
==========================================
- Hits         1274     1270       -4     
- Misses        224      232       +8     

Impacted Files	Coverage Δ
src/mp_api/core/settings.py	100.00% <ø> (ø)
src/mp_api/routes/alloys.py	76.92% <25.00%> (-23.08%)	⬇️
src/mp_api/client.py	68.38% <0.00%> (-1.11%)	⬇️
src/mp_api/core/client.py	87.64% <0.00%> (-0.58%)	⬇️

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