Remove aggregate in build.sbt
Remove aggregate in build.sbt

The release for M5 failed because of duplicate releases of some modules.
This commit reverts the build to have the same structure as in M4, when
the release succeeded.

scalameta/scalameta,scalameta/scalameta,olafurpg/scalameta,scalameta/scalameta,scalameta/scalameta,xeno-by/scalameta,scalameta/scalameta,xeno-by/scalameta,xeno-by/scalameta,olafurpg/scalameta,olafurpg/scalameta