Build/Test Tools: Improve the accuracy of “fixed” Slack notifications.

This adjusts the logic of the Slack Notifications workflow to make the “fixed” notifications more reliable.

Currently, the workflow looks at the immediately preceding workflow run for the current branch. This fails to indicate that a workflow is fixed when other unrelated commits are made, and when rerunning the workflow after a false failure (timeout, etc.).

The workflow will now use the following logic to determine if something has been fixed:
- When a workflow is rerun, the conclusion for the immediately preceding run attempt will now be used to determine if the current attempt has “fixed” the workflow.
- When on the first run attempt for a workflow run, the workflow conclusion for the immediately preceding commit will be used.
- When on the first run attempt for a workflow run and no preceding commits for the current branch are present (this is a fresh tag or branch), always consider it “fixed”.

Props davidbaumwald.
See #54742.
Built from https://develop.svn.wordpress.org/trunk@53108


git-svn-id: http://core.svn.wordpress.org/trunk@52697 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-53107';
+$wp_version = '6.0-alpha-53108';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.