Implememt automatic milestone mechanism

[RobPasMue]

📝 Description of the feature

We should be able to notify all the core dependencies (at the very least) that they should prepare to have a milestone ready before Ansys release (e.g. 23R1, 23R2...).

This should be done as a GH Actions workflow using the PyGithub package (allows to automatically interact with GitHub's API from Python)

💡 Steps for implementing the feature

To be determined

🔗 Useful links and references

No response

[RobPasMue]

We should create a milestone in all the core dependencies some weeks prior to the Ansys Dev Complete date.