Remediate AWS CDK Deprecations

[mwarman]

Describe the task

Address AWS CDK deprecation warnings in the infrastructure code.

• [WARNING] aws-cdk-lib.aws_rds.CfnDBInstance#tdeCredentialArn is deprecated. this property has been deprecated This API will be removed in the next major release.
• [WARNING] aws-cdk-lib.aws_rds.CfnDBInstance#tdeCredentialPassword is deprecated. this property has been deprecated This API will be removed in the next major release.
• [WARNING] aws-cdk-lib.aws_ecs.CfnTaskDefinition#inferenceAccelerators is deprecated. this property has been deprecated This API will be removed in the next major release.

Additional context

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