Update nscplugin, sbt-scala-native to 0.5.0 (#716)

update version policy for minor release

Merge pull request #678 from dubinsky/equality-inequality

Equality cleanup:

Update sbt-scala-native-crossproject, ... to 1.2.0

Merge pull request #542 from SethTisue/issue541

add Scala 3.0.0 to crossbuild (and drop -RC2) (#522)

backpublish 2.0.0-RC1 for Scala 3.0.0-RC3

Merge pull request #503 from SethTisue/scala-3.0.0-RC2

support Scala 3.0.0-RC1 (and drop 3.0.0-M2) (#493)

Merge pull request #482 from lolgab/support-scala-native