Verify steps update

[tkobayas]

Updated the verify steps for reviewer's convenience.

[LightGuard]

I thought we had a .rat-excludes file. Shouldn't that be used?

[tkobayas]

We want to verify all files in our first attempt of thorough license check. In the future (10.1.0 or rc5), we can use .rat-excludes to exclude confirmed files.

Indeed, I have filed apache/incubator-kie-issues#1613 to ease the release verification step. But while working on the license fixes, I realized that "excluded files" are the important files to check. It is the thing to be verified by the release verification, per my understanding.

Current .rat-excludes files are equivalent to Files with unapproved licenses: of rat-result.txt (a rat check report without exclusion). So if Files with unapproved licenses: is reviewed in this rc4 release verification step, we can use .rat-excludes next time.

[jomarko]

I agree with the first release, we can ask people to not use .rat-excludes files. Yes, then once release is approved, we can assume our exclude files are correct, and we can start to use them, we do not need more verify their correctness.

Also I think we can be much more confident about the .rat-excludes files once we start to use [email protected], as that version has support for full patch in the exclude file. See my issue for future improvement apache/incubator-kie-issues#1670