feat(rds): support Aurora MySQL 8.4.7

[Tietew]

Issue # (if applicable)

Closes #37924.

Reason for this change

Aurora MySQL 8.4.7 is now GA.
https://aws.amazon.com/blogs/database/amazon-aurora-mysql-8-4-is-now-generally-available/

Description of changes

Added the Aurora MySQL 8.4.7 support to AuroraMysqlEngineVersion.

Describe any new or updated permissions being added

N/A

Description of how you validated changes

WIP: Added unit tests and updated integ tests.

Following integ tests contain destructive changes, which are expected change due to major version upgrade (AWS::RDS::DBCluterParameterGroup will be replaced)

• integ.cluster-replication.js
• integ.cluster-s3.js
• integ.cluster-s3.mysql-8.js
• integ.cluster-s3.mysql-engine-version.js
• integ.cluster.js

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[aws-cdk-automation]

The pull request linter fails with the following errors:

❌ Features must contain a change to a README file.
❌ Features must contain a change to an integration test file and the resulting snapshot.

If you believe this pull request should receive an exemption, please comment and provide a justification. A comment requesting an exemption should contain the text Exemption Request. Additionally, if clarification is needed, add Clarification Request to a comment.

✅ A exemption request has been requested. Please wait for a maintainer's review.

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
This security report is NOT a review blocker. Please try merge from main to avoid findings unrelated to the PR.
To suppress a specific rule, see Suppressing Rules.

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	Tests	Passed ☑️	Skipped	Failed ❌️
Security Guardian Results	744 ran	743 passed		1 failed

Test	Result
Security Guardian Results
packages/@aws-cdk-testing/framework-integ/test/aws-rds/test/integ.cluster-rotation.lit.js.snapshot/aws-cdk-rds-cluster-rotation.template.json
ec2-no-open-security-groups.guard	❌ failure

• View Security Guardian Results

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
This security report is NOT a review blocker. Please try merge from main to avoid findings unrelated to the PR.
To suppress a specific rule, see Suppressing Rules.

---

	Tests	Passed ✅	Skipped	Failed
Security Guardian Results with resolved templates	744 ran	744 passed

Test	Result
No test annotations available

• View Security Guardian Results with resolved templates

[Tietew]

Exemption Request

The README does not refer detailed engine version. Changing README isn't needed.
Integ tests are updated to latest engine version. No new integ test are needed.