Prerelease version not validating successfully

[tobias-graf-p]

The version v1.2.0-alpha.9 validates successfully while v1.2.0-alpha.10 is not validating successfully anymore. I assume the regex does not handle 2+ digit prerelease versions properly.

Moreover - when looking at the regex in the source - I wonder why the v prefix is validating successfully. I don't see it in the regex. I assume there should be a v? part at the very beginning of the regex. But still the above version validates successfully. Why is this?