Make caching of LTA and LTC Version and RunnerOs Aware

[danielsiegl]

We can use the public XML files used for other stuff to determine the current "latest" and use this info for the cache key.

https://customers.lieberlieber.com/downloads/LemonTree/Connect/Polarion/LemonTree.Connect.Polarion.xml
https://customers.lieberlieber.com/downloads/LemonTree/LemonTreeVersion.xml

[danielsiegl]

Or try to use the simpler pattern from GitLab by using my custom docker image:

https://github.com/danielsiegl/LemonTree.Automation.Custom.Docker

on GitLab it helped dramaticly to speed up builds - as GitLab caches the images automatically

[danielsiegl]

Maybe a startingpoint could be a custom workflow that runs consistency check inside the Docker Image