Do not attempt Gutenberg workaround when not running locally

[mokagio]

A quick followup to #21961 – Not sure how it worked before this change, given that the code called in the post_integrate was defined after the private directive 🤔

Anyways, this should set things straight and avoid unnecessary loops.

For context: I noticed this because I my project file was all messed up with no Gutenberg framework and I went to look into my Podfile settings. I didn't found the cause for my project file issue, but noticed this.

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📲 You can test the changes from this Pull Request in WordPress Alpha by scanning the QR code below to install the corresponding build.

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr22035-0fb7e02
	Version	23.7
	Bundle ID	org.wordpress.alpha
	Commit	0fb7e02
	App Center Build	WPiOS - One-Offs #7876

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[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack Alpha by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr22035-0fb7e02
	Version	23.7
	Bundle ID	com.jetpack.alpha
	Commit	0fb7e02
	App Center Build	jetpack-installable-builds #6900

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[dcalhoun]

I verified both bundle exec pod install and LOCAL_GUTENBERG=1 bundle exec pod install succeed, and subsequent builds succeeded. 🚀