Remove an unused source file: LocalizationConfiguration.swift

[crazytonyli]

This file is not used in any target. Also, it seems to be a duplication of WordPress/JetpackStatsWidgets/LocalizationConfiguration.swift. It's potentially a left-over from #21521.

This PR should be good to merge as long as CI jobs pass.

Regression Notes

1. Potential unintended areas of impact
   None.

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   None.

3. What automated tests I added (or what prevented me from doing so)
   None.

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

UI Changes testing checklist: N/A

[wpmobilebot]

📲 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	pr21784-36ca389
	Version	23.4
	Bundle ID	org.wordpress.alpha
	Commit	36ca389
	App Center Build	WPiOS - One-Offs #7412

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[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	pr21784-36ca389
	Version	23.4
	Bundle ID	com.jetpack.alpha
	Commit	36ca389
	App Center Build	jetpack-installable-builds #6442

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[mokagio]

With this removal: CI is green and there's no project file change. Looks good.