Tools: add PHPUnit Polyfills

[jrfnl]

---

name: 🎉 New Feature
about: Add a new feature
labels: enhancement

A Pull Request should be associated with a Discussion.

Fixes #502

Description

This PR adds support for the PHPUnit Polyfills tool via the tools input to setup-php.

I have added a test to the linux test and a second test with a specific version to the darwin test.

In case this PR introduced TypeScript/JavaScript code changes:

• I have written test cases for the changes in this pull request
• I have run npm run format before the commit.
• I have run npm run lint before the commit.
• I have run npm run release before the commit.
• npm test returns with no unit test errors and all code covered.

Note: running these scripts, automatically added two unrelated changes to the PR, which I have manually removed (had to disable the pre-commit hook to do so). The changes were to package-lock.json and to dist/index.js. Not sure what's going on there.

In case this PR edits any scripts:

• I have checked the edited scripts for syntax.
• I have tested the changes in an integration test (If yes, provide workflow YAML and link).

[shivammathur]

Please remove dist/index.js.bak file from the PR.

[jrfnl]

Yikes! Sorry about that, not sure how that got in there as I have a git global ignore set up for those type of files... Either way, should be fixed now.

[shivammathur]

@jrfnl Thanks!

[jrfnl]

Thanks @shivammathur !

[jrfnl]

Integration test:

• Yaml changes: jrfnl/PHPMailer@342ad9b
• Successful action run: https://github.com/jrfnl/PHPMailer/actions/runs/1255741429

[jrfnl]

FYI: I've added an FAQ section to the README for the PHPUnit Polyfills about using it via setup-php with tools:
https://github.com/Yoast/PHPUnit-Polyfills#q-how-do-i-run-my-tests-when-the-library-is-installed-via-the-github-actions-setup-php-action-