wpcomsh: Prevent PHP fatals when footer is nested in an output buffer

[tbradsha]

Closes MONOREP-174

This addresses the following fatals:

PHP Fatal error: preg_split(): Cannot use output buffering in output buffering display handlers in /wordpress/plugins/wpcomsh/8.1.0-alpha+rolling.1761763643.g48b79fe/footer-credit/footer-credit-optimizations.php on line 20
PHP Fatal error: wpcom_better_footer_links_buffer(): Cannot use output buffering in output buffering display handlers in /wordpress/plugins/wpcomsh/8.1.0-alpha+rolling.1761916560.gcfb3b38/footer-credit/footer-credit-optimizations.php on line 28
PHP Fatal error: preg_replace(): Cannot use output buffering in output buffering display handlers in /wordpress/plugins/wpcomsh/8.1.0-alpha+rolling.1761763643.g48b79fe/footer-credit/footer-credit-optimizations.php on line 36

I wasn't able to reproduce this, but it should be a safe change, and is more efficient, too (no regex stuff):

• preg_split() → explode(): both limit to two, but now it's not case-insensitive (nor does it need to be from what I can see)
• implode( array() ) → string concatenation: I'm not sure why it was anything but this originally
• preg_replace() → str_replace(): now it's not case-insensitive (nor does it need to be from what I can see)

Proposed changes:

Other information:

• Have you written new tests for your changes, if applicable?
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Testing instructions:

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[github-actions]

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• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (WordPress.com Site Helper), and enable the fix/wpcomsh/fix_footer_fatals branch.

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Code Coverage Summary

This PR did not change code coverage!

That could be good or bad, depending on the situation. Everything covered before, and still is? Great! Nothing was covered before? Not so great. 🤷

Full summary · PHP report

[anomiex]

🤷 I don't think this will break anything, but I also don't think it's likely it'll actually fix the messages.