Add contributing guidelines around Component versioning

[ciampo]

Related to #58324

What?

This PR introduces a section in the Contributing Guidelines of the @wordpress/components package to standardize the procedure of introducing a new version of an existing component.

Why?

We've been recently working on introducing new version of existing components (Tooltip, TabPanel, CustomSelectControl, DropdownMenu, Composite). While working on it, we gathered experience on what worked well, and we thing it's a good idea to standardize the process for future work.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

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Co-authored-by: ciampo <mciampini@git.wordpress.org>
Co-authored-by: mirka <0mirka00@git.wordpress.org>

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[github-actions]

Flaky tests detected in 0f84f5c.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/7848307301
📝 Reported issues:

• [Flaky Test] aria-disabled is correctly hydrated for different values #54370 in /test/e2e/specs/interactivity/directive-bind.spec.ts

[mirka]

Thanks for writing this up!