Drop mirrors.yml workflow from GitHub actions, passing but trying to update a non-existent production repository. The production repositories project is on hold, and we can restore the workflow if the project gets traction.
* Added Monorepo Setup Action
This action will handle the installation, building, and caching for all
projects within the monorepo. It has inputs for skipping builds and
filtering so that only specific packages are installed and built.
* Removed Test Caching
Caching the results of tests, while an interesting way to avoid
unnecessary execution, seems error-prone. We can't adequately
capture the environment such that we can rely on this working.
For instance, changes in PHP version might break PHPUnit tests,
but, cached runs will be shared across different workflows.
It seems better to just not cache it and rely on people only testing
code that has actually changed in the pull request.
* Added Input Parsing
This SHOULD allow for passing multiple filters as an array argument.
* Updated Workflows
This fully utilizes the new action across all of the workflows.
* Always Cache Build Output
Since there may be other commands run that populate the cache, we
should make sure that we are always caching just in case.