Build: Let revapi compare against 1.1.0

[nastra]

We should merge this once 1.1.0 has been released

[gaborkaszab]

@nastra While being a release manager for 1.1.0 I made list of improvements I'd like to add to the "how-to-release" page. Do you think I should add this step also to the list to make revapi work for the new release?

[ajantha-bhat]

@gaborkaszab: I think we should add. And also this one
#6287

Please tag me for the review of the "how to release" update.

One more change that I would like to have it in how to release is to finish (or keep it ready) the document site PR before voting. So, once the voting passes we can announce the release quickly just after pushing release candidate to the maven repo. This way release will be more smoother (less confusing)
This time the delta between document update and maven jars publishing was a day or two (it is much better compared to previous times). But can still be better :)

[nastra]

@gaborkaszab yes it would make sense to add an item to the list that mentions that RevAPI needs to be updated to compare against the released version