[Code Gen] Update Sourcery library to latest version

[selanthiraiyan]

Closes: #15215

Description

Running rake generate for copiable and fakeable code generation throws errors in trunk.

This PR updates Sourcery to the latest version to fix this issue.

Steps to reproduce

• Unit tests should pass.
• Run rake generate from trunk and ensure that there are no errors.

Testing information

• Ensured that rake generate works without errors.

Screenshots

NA

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• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Reviewer (or Author, in the case of optional code reviews):

Please make sure these conditions are met before approving the PR, or request changes if the PR needs improvement:

• The PR is small and has a clear, single focus, or a valid explanation is provided in the description. If needed, please request to split it into smaller PRs.
• Ensure Adequate Unit Test Coverage: The changes are reasonably covered by unit tests or an explanation is provided in the PR description.
• Manual Testing: The author listed all the tests they ran, including smoke tests when needed (e.g., for refactorings). The reviewer confirmed that the PR works as expected on all devices (phone/tablet) and no regressions are added.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 21.8. This milestone is due in less than 2 days. Please make sure to get it merged by then or assign it to a milestone with a later deadline.

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

	App Name	WooCommerce iOS
	Build Number	pr15216-f504449
	Version	21.7
	Bundle ID	com.automattic.alpha.woocommerce
	Commit	f504449
	App Center Build	WooCommerce - Prototype Builds #13099

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[rachelmcr]

Works great, thanks for taking care of this update!