Update Lambda Runtime (pyhton 3.9 to 3.11)

I have many lambdas were created with CDK and I want to update the runtime. I've done these changes:

• I Updated python 3.11 in Cloud9 (also in venv)
• I Changed the CDK code where modify the runtime like this:

runtime=lambda_.Runtime.PYTHON_3_9  -> runtime=lambda_.Runtime.PYTHON_3_11

But I get this error when I try to deploy: RuntimeError: This lambda function uses a runtime that is incompatible with this layer (python3.11 is not in [python3.9])

This is part of the content of my requirements.txt file:

aws-cdk-lib==2.118.0
aws-cdk.aws-lambda-python-alpha==2.118.0a0
aws_ddk_core==1.4.0
boto3==1.34.12

Why Do I get that error? What have to do if I want to update the runtime?