Merge pull request scala#12195 from smarter/require-sbt-1.5

sbt-dotty: Require sbt >= 1.5.0, deprecate withDottyCompat

Set version to 3.0.0-RC3

Merge pull request scala#11947 from dotty-staging/deprecate-sbt-dotty

Deprecate sbt-dotty when using sbt >= 1.5.0-RC2

Merge pull request scala#11926 from dotty-staging/fix-11922

Eta expand exported type constructors

Set version to RC1

Merge pull request scala#11431 from dotty-staging/fix-11430

Move checkValue to Typer

Publish sbt-dotty 0.5.2

Merge pull request scala#10843 from romanowski/scal3doc/fix-empty-pro…

…jects

Fix support for project with no sources

Merge pull request scala#10819 from romanowski/fix-ci

Force full compilation in malformed-class-name-with-dollar

Merge pull request scala#10773 from dotty-staging/bump-sbt-dotty-0.5

sbt-dotty: Require sbt >= 1.4, bump version to 0.5.0-SNAPSHOT