fix: revert bump to 0.10.7

There are some legit cask failures when you bump. Plus it's
still on 0.10.5, so leave it as is

Author: ckipp01

community-build/src/scala/dotty/communitybuild/projects.scala

@@ -99,7 +99,7 @@ final case class MillCommunityProject(
     // uncomment once mill is released
     // if ignoreDocs then null else s"$baseCommand.docJar"
   override val runCommandsArgs = List("-i", "-D", s"dottyVersion=$compilerVersion")
-  override val environment = Map("MILL_VERSION" -> "0.10.7")
+  override val environment = Map("MILL_VERSION" -> "0.10.5")
 
 final case class SbtCommunityProject(
     project: String,