dm: Add MySQL 8.4 info to compatibility catalog

[dveeden]

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[gemini-code-assist]

Summary of Changes

Hello @dveeden, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request updates the TiDB Data Migration (DM) compatibility catalog to include information about newer MySQL versions. The primary goal is to provide users with a clearer understanding of which MySQL versions are compatible, incompatible, or untested with DM, particularly highlighting the incompatibility of MySQL 8.4 and noting the status of other recent and future versions.

Highlights

• MySQL Compatibility Updates: Added new entries to the DM compatibility catalog for MySQL versions 8.1, 8.2, 8.3, 8.4, and 9.x, clarifying their support status with TiDB Data Migration (DM).
• MySQL 8.4 Incompatibility Noted: Specifically marked MySQL 8.4 as 'Incompatible' with DM, referencing a relevant TiFlow issue (pd: add rank-formula-version config for hot scheduler (#10936) #11020) for further details.
• Future MySQL Versions: Included 'Not tested' statuses for MySQL 8.1-8.3 and 9.x, indicating that these versions have not yet been officially validated for compatibility.

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[gemini-code-assist]

Code Review

This pull request updates the DM compatibility catalog to include information for MySQL versions 8.1 through 8.4, and 9.x. The changes are accurate and clear. I've added a couple of minor suggestions to improve consistency and provide more context for the user.

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-11-10 10:53:43.087325284 +0000 UTC m=+699472.530355163: ☑️ agreed by lance6716.
• 2025-11-12 03:29:46.213617956 +0000 UTC m=+845635.656647835: ☑️ agreed by hfxsd.

[hfxsd]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hfxsd

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.5: #22045.