Use new check-sdist-action for build-package CI

[CasperWA]

Based on the original build-package CI job I have created the GH Action check-sdist-action.

This PR updates the build-package job to use this action.

[codecov]

Codecov Report

Merging #214 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #214   +/-   ##
========================================
  Coverage    35.67%   35.67%           
========================================
  Files           17       17           
  Lines         2161     2161           
========================================
  Hits           771      771           
  Misses        1390     1390           

Flag	Coverage Δ
optimade-client	35.67% <ø> (ø)

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