aws-rds: serverlessV2 auto-pause feature is not supported by aurora-mysql 8.4.mysql_aurora.8.4.7

### Describe the bug

I'm upgrading to Aurora MySQL version 8.4. I'm coming from version 3.12.

I decided to upgrade manually for testing purposes. I updated the user passwords, did everything, and the application is working correctly.

When updating the AWS CDK code (to prevent drift), I encountered the following error:

### Regression Issue

- [ ] Select this option if this issue appears to be a regression.

### Last Known Working CDK Library Version

_No response_

### Expected Behavior

It should support this feature since it's the latest version, and yesterday they announced improvements even beyond the potential of version 4 of the platform.

### Current Behavior

Same error description

### Reproduction Steps

Simply the basic use of deploying a serverlessv2 database with the latest version of Aurora 8.4

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### AWS CDK Library version (aws-cdk-lib)

2.260.0

### AWS CDK CLI version

2.1129.0

### Node.js Version

24.19

### OS

Linux

### Language

TypeScript

### Language Version

6.0.3

### Other information

_No response_

The issue names no source file or test. Start by reproducing a serverlessv2 database using Aurora MySQL 8.4.mysql_aurora.8.4.7 with aws-cdk-lib 2.260.0, then trace the aws-rds engine-version and auto-pause validation entry points. Done means the configuration is accepted for this engine version and regression coverage verifies it.

Written by the indexing model from the issue text.