Add MacOS check and test to CI

[neeldug]

adds macos checks and tests to pull request ci

It changes the following:

• automated testing and checks to include MacOS using GitHub Actions

[codecov]

Codecov Report

Merging #744 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #744   +/-   ##
=======================================
  Coverage   71.75%   71.75%           
=======================================
  Files         200      200           
  Lines       13983    13983           
=======================================
  Hits        10033    10033           
  Misses       3950     3950           

Impacted Files	Coverage Δ
tester/src/results.rs
tester/src/read.rs
tester/src/main.rs
tester/src/exec.rs
boa_tester/src/exec.rs	0.00% <0.00%> (ø)
boa_tester/src/results.rs	0.00% <0.00%> (ø)
boa_tester/src/read.rs	0.00% <0.00%> (ø)
boa_tester/src/main.rs	0.00% <0.00%> (ø)

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