Scala 2.12.15 doesn't like Java 21?

That's quite surprising

Author: cb372

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
           - 3.4.2
         java:
           - 11
-          - 21
+          - 17
     runs-on: ubuntu-latest
     steps:
       - name: Checkout

.github/workflows/release.yml

@@ -15,10 +15,11 @@ jobs:
           fetch-depth: 0 # fetch all tags to make sbt-dynver work properly
 
       - name: Setup Java and Scala
-        uses: olafurpg/setup-scala@v13
-
-      - name: Cache sbt
-        uses: coursier/cache-action@v6
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'adopt'
+          java-version: 17
+          cache: 'sbt'
 
       - name: Publish
         run: sbt ci-release