Build/Test Tools: Update all 3rd party actions to their latest versions.

This updates all 3rd party GitHub actions to their latest versions.

- `actions/cache` from `2.1.6` to `3.0.1`.
- `actions/github-script` from `5.0.0` to `6.0.0`.
- `actions/setup-node` from `2.4.1` to `3.1.0`.
- `codecov/codecov-action` from `2.1.0` to `3.0.0`.
- `ramsey/composer-install` from `1.3.0` to `2.1.0`.
- `shivammathur/setup-php` from `2.15.0` to `2.18.0`.

Additionally, this updates all instances of the `actions/setup-node` action to replace the `node-version` option with the new `node-version-file`. This simplifies the process of changing the version of NodeJS used in workflows by only requiring the version to be changed once in the `.nvmrc` file.

See #54725.
Built from https://develop.svn.wordpress.org/trunk@53112


git-svn-id: http://core.svn.wordpress.org/trunk@52701 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-53111';
+$wp_version = '6.0-alpha-53112';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.