Updated changelog for beta release and backfilled last hotfix

[MSeal]

Backfills the changelog for the beta release (separate branch)

Checklist

• Contains customer facing changes? Including API/behavior changes
• Did you add sufficient unit test and/or integration test coverage for this PR?
  • If not, please explain why it is not required

References

JIRA:

Test & Review

Open questions / Follow-ups

[confluent-cla-assistant]

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[Copilot]

Pull request overview

This PR updates the changelog to document a beta release (v2.13.0b1) and backfills the missing v2.12.2 hotfix entry. The changelog now properly reflects the chronological sequence of releases with the beta release's comprehensive list of changes and the hotfix's critical Schema Registry fix.

Key Changes:

• Added beta release v2.13.0b1 entry with 13 feature/fix items
• Backfilled missing v2.12.2 hotfix entry documenting the Schema Registry fix

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[Copilot]

Corrected spelling of 'interaces' to 'interfaces'.

Suggested change

	- Enforced type hinting for all interaces
	- Enforced type hinting for all interfaces

[sonarqube-confluent]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube