Add skill to bump min supported version in the python guidelines

[swathipil]

We want to add a skill (or investigate a better alternative) that will automatically create a PR to update the hardcoded minimum supported Python version in these two files in the Azure/azure-sdk repo:

• https://github.com/Azure/azure-sdk/blob/main/docs/python/design.md
• https://github.com/Azure/azure-sdk/blob/main/docs/policies/support.md

The min supported version should be bumped when SDKs end of support is reached, as per table here:https://github.com/Azure/azure-sdk-for-python/blob/main/doc/python_version_support_policy.md