PCS Image Builder component missing 25.05

[javydekoning]

Our code here:
https://github.com/aws-samples/aws-hpc-recipes/blob/main/recipes/pcs/login_node_for_res/assets/imagebuilder-components.yml

Doesn't support 25.05.

I suggest we remove the validation here: https://github.com/aws-samples/aws-hpc-recipes/blob/main/recipes/pcs/login_node_for_res/assets/imagebuilder-components.yml#L23-L25

And replace it with:

AllowedPattern: '^\d{2}\.\d{2}$'

In the description of the parameter we link to: https://docs.aws.amazon.com/pcs/latest/userguide/slurm-versions.html

Otherwise this component will always lag behind.