This is exactly what I was thinking would be the next step. I didn’t have the time to do this myself. But I am happy with changing the version and manually clearing the cache for now. Thank you for all the help @John_B!
Also I think it would be good to add this info to the docs somewhere. One could customize the build environment this way and cache their build tools too. It’s sort of similar to what other CI services offer in their pipelines.