Update sbt-assembly to 1.0.0 (#2161)

Author: scala-steward

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.codecommit" % "sbt-github-actions" % "0.12.0")
-addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.15.0")
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "1.0.0")
 addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.10.0")
 addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.5.7")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.2")