Fix Scala 3 binary version

[adpi2]

Fixes sbt/sbt#6585

The binary version of 3.x.y-foo-bar should be 3 if x > 0 or y > 0.

Example:

• for 3.0.1-bin-nonbootstrapped it should be 3
• for 3.0.1-SNAPSHOT it should be 3

@smarter @prolativ

[prolativ]

Not sure if we should care about versions with missing patch number like 3.1 or 3.2-bin-foo or not. In theory this shouldn't be a problem if we never decide to release such versions

[smarter]

Compiler version numbers should always have a patch field yes.

[eed3si9n]

Thanks!