MAINTENANCE: Use independent release branches for each minor version

[RobPasMue]

I have observed that you have been using the same release/0.2 branch for all your releases. The purpose of release/x.y branches is to ease the process of releasing and keep them independent, since there could be breaking changes between minor releases, and we might be required to patch release them...

See this case, for example:

• We have releases 0.2.x'' and 0.3.x`` currently
• A security vulnerability is detected and we are required to patch release all our current minor releases

With your current release procedure, it would be impossible for you to patch release 0.2.x. That is the reason why independent minor release branches are required in our repositories: release/0.2, release/0.3

Please apply this good practice team: @ansjmoody @ansnfernand @ansnraines
CCing @ansys/pyansys-core for visibility - we should make sure all repos are releasing properly.