Bump actix web

[Luni-4]

This PR updates actix-web to version 4.1 that removes a lot of third-party dependencies. Should be merged after #882

[codecov-commenter]

Codecov Report

Merging #883 (775c906) into master (dcb2723) will decrease coverage by 0.01%.
The diff coverage is 32.25%.

@@            Coverage Diff             @@
##           master     #883      +/-   ##
==========================================
- Coverage   42.50%   42.49%   -0.02%     
==========================================
  Files          55       55              
  Lines        8178     8166      -12     
  Branches     1200     1199       -1     
==========================================
- Hits         3476     3470       -6     
+ Misses       3896     3885      -11     
- Partials      806      811       +5     

Impacted Files	Coverage Δ
rust-code-analysis-web/src/web/server.rs	62.89% <32.25%> (+0.36%)	⬆️
src/langs.rs	90.00% <0.00%> (-10.00%)	⬇️
src/spaces.rs	73.88% <0.00%> (+0.55%)	⬆️

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