chore(rds): add MySQL version 8.4.7

[Tietew]

Reason for this change

A new MySQL engine version is available.

No announcements are published yet.

Description of changes

• Added a MySQL engine version 8.4.7

Describe any new or updated permissions being added

N/A

Description of how you validated changes

$ aws --region us-east-1 rds describe-db-engine-versions --engine 'mysql' --query 'DBEngine
Versions[].EngineVersion' --output table
--------------------------
|DescribeDBEngineVersions|
+------------------------+
|  5.7.44-rds.20240408   |
|  5.7.44-rds.20240529   |
|  5.7.44-rds.20240808   |
|  5.7.44-rds.20250103   |
|  5.7.44-rds.20250213   |
|  5.7.44-rds.20250508   |
|  5.7.44-rds.20250818   |
|  8.0.37                |
|  8.0.39                |
|  8.0.40                |
|  8.0.41                |
|  8.0.42                |
|  8.0.43                |
|  8.4.3                 |
|  8.4.4                 |
|  8.4.5                 |
|  8.4.6                 |
|  8.4.7                 |
+------------------------+

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

[mergify]

Thank you for contributing! Your pull request will be updated from main and then merged automatically (do not update manually, and be sure to allow changes to be pushed to your fork).

[mergify]

Thank you for contributing! Your pull request will be updated from main and then merged automatically (do not update manually, and be sure to allow changes to be pushed to your fork).

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