Adjust build and automated tests

[jakejackson1]

Description

Still having trouble building Gravity PDF due to the custom @wordpress/env package. This PR swaps back to yarn to check if the new node_modules caching running on GitHub Actions fixes the problem.

Testing instructions

The automated tests will handle it.

Checklist:

• [x] I've tested the code.
• [ ] My code is easy to read, follow, and understand
• [ ] My code follows the accessibility standards.
• [ ] My code has proper inline documentation / docblocks.

Additional Comments

[codecov[bot]]

Codecov Report

Merging #1381 (c1bc089) into development (d653487) will not change coverage. The diff coverage is n/a.

:exclamation: Current head c1bc089 differs from pull request most recent head 81799ca. Consider uploading reports for the commit 81799ca to get more accurate results

@@             Coverage Diff              @@
##           development    #1381   +/-   ##
============================================
  Coverage        93.30%   93.30%           
============================================
  Files               57       57           
  Lines             1464     1464           
  Branches           370      370           
============================================
  Hits              1366     1366           
  Misses              90       90           
  Partials             8        8