fix: check if get_current_screen() is set before accessing properties

[justlevine]

What

This PR fixes the usage of get_current_screen() to check if it's set, before attempting to access properties.

Why

It can cause a fatal php error. Personally, it's getting in the way of my unit tests.

To test

<?php
// functions.php
  do_action( 'admin_notices' );

If it doesnt error, it worked. Or just run composer phpstan and confirm it's passing even though the ignore rule has been removed from the baseline.

[changeset-bot]

🦋 Changeset detected

Latest commit: 6ced628

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@wpengine/wp-graphql-content-blocks	Patch

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[justlevine]

Those failed tests predate, and are unrelated to, the changes in this PR.

[justlevine]

Anything I can do to help get this merged? Hoping to do a sprint of contributions this/next week and it would be nice not to workaround this 🤞

[jasonbahl]

@justlevine it looks like tests are fine on other PRs but not this one? 🤔

[justlevine]

@jasonbahl i've rebased the branch on main, so hopefully caught the upstream issue: