Build/Test Tools: Temporarily ignore Slack failures.

When many workflows are initiated at the same time, there are often instances where the requests to Slack providing updates are rate limited. This usually happens when the Test Old Branches workflow runs and initiates testing for all workflows in branches that could potentially receive a security update.

Even though everything was successful in the workflow except the message, the workflow run is marked as failed. The next time the same workflow runs for that branch, a “fixed” message will be sent to `#core` in Slack. The result is a burst of messages that is quite noisy and unnecessary.

This temporarily adds `continue-on-error` to the jobs responsible for sending the messages until a better solution can be decided on.

See #61701.
Built from https://develop.svn.wordpress.org/trunk@59209


git-svn-id: http://core.svn.wordpress.org/trunk@58604 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.7-beta2-59208';
+$wp_version = '6.7-beta2-59209';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.