actually use JDK21 for JDK21 CI

- don't load artifacts built with old scala versions per
  https://docs.scala-lang.org/overviews/jdk-compatibility/overview.html
- ignore tests with hardcoded old sbt versions, since these were built with
  Scala versions not supported by JDK21 - we need a way to run these tests
  with max(scriptedSbt, build.properties) if we want to re-enable them

.github/workflows/ci.yml

@@ -37,10 +37,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: olafurpg/setup-scala@v14
+      - uses: coursier/setup-action@v1
         with:
-          jvm: temurin:17
-      - run: sbt "test; scripted sbt-*/* skip-windows/*"
+          jvm: temurin:21
+      - run: sbt "test; scripted sbt-scalafix/* skip-windows/*"
   windows:
     name: Windows tests
     runs-on: windows-latest

src/sbt-test/sbt-scalafix/dependency/build.sbt

@@ -1,4 +1,4 @@
-scalaVersion := "2.12.7"
+scalaVersion := "2.12.18"
 
 TaskKey[Unit]("check") := {
   val a = IO.read((Compile / sourceDirectory).value / "scala" / "A.scala")

src/sbt-test/sbt-scalafix/local-rules/build.sbt

@@ -7,7 +7,7 @@ inThisBuild(
       "ch.epfl.scala" %% "example-scalafix-rule" % "1.4.0"
     ),
     resolvers += Resolver.sonatypeRepo("snapshots"),
-    scalaVersion := "2.13.0", // out of sync with scalafix.sbt.BuildInfo.scala213 on purpose
+    scalaVersion := "2.13.11", // out of sync with scalafix.sbt.BuildInfo.scala213 on purpose
     scalafixScalaBinaryVersion :=
       // this should be the default in sbt-scalafix 1.0
       CrossVersion.binaryScalaVersion(scalaVersion.value)
@@ -24,7 +24,7 @@ val rules = project
 val service = project
   .dependsOn(rules % ScalafixConfig)
   .settings(
-    libraryDependencies += "com.nequissimus" %% "sort-imports" % "0.5.2" % ScalafixConfig
+    libraryDependencies += "ch.epfl.scala" %% "example-scalafix-rule" % "3.0.0" % ScalafixConfig
   )
 
 val sameproject = project

src/sbt-test/sbt-scalafix/local-rules/test

@@ -10,6 +10,6 @@ $ delete rules/src/main/scala/local/NoOp.scala
 > service/scalafix SyntacticRule
 
 # run a rule included from a remote JAR referenced via the Scalafix ivy config
-> service/scalafix SortImports
+> service/scalafix SyntacticRule
 
 > sameproject/scalafix SameProjectSyntacticRule

src/sbt-test/skip-windows/caching/test

@@ -335,7 +335,7 @@ $ mkdir src/main/scala
 $ copy-file files/Valid.scala src/main/scala/Valid.scala
 > scalafix --check ProcedureSyntax
 > reload plugins
-> 'set dependencyOverrides += "ch.epfl.scala" % "scalafix-interfaces" % "0.9.17+5-86d5550d-SNAPSHOT"' // different than current, requires bumping when using new APIs
+> 'set dependencyOverrides += "ch.epfl.scala" % "scalafix-interfaces" % "0.11.0"' // different than current, requires bumping when using new APIs
 > session save
 > reload return
 $ exec chmod 000 src/main/scala/Valid.scala
@@ -349,7 +349,7 @@ $ copy-file files/Valid.scala src/main/scala/Valid.scala
 > set scalafixDependencies in ThisBuild := Nil
 > scalafix --check ProcedureSyntax
 > reload plugins
-> 'set dependencyOverrides += "ch.epfl.scala" % "scalafix-interfaces" % "0.9.17+7-a1b6d972-SNAPSHOT"' // different than above, requires bumping when using new APIs
+> 'set dependencyOverrides += "ch.epfl.scala" % "scalafix-interfaces" % "0.11.0+134-f4dcc6fa-SNAPSHOT"' // different than above, requires bumping when using new APIs
 > session save
 > reload return
 > set scalafixDependencies in ThisBuild := Nil