ci: switch CodeQL to actions scan for scala-only repo

Author: vim89

.github/workflows/ci.yml

@@ -124,19 +124,10 @@ jobs:
       - uses: actions/checkout@v5
         with:
           fetch-depth: 0
-      - uses: sbt/setup-sbt@v1
-      - uses: actions/setup-java@v4
-        with:
-          distribution: temurin
-          java-version: 17
-          cache: sbt
       - name: CodeQL init
         uses: github/codeql-action/init@v4
         with:
-          languages: java
-          build-mode: manual
-      - name: CodeQL build (sbt)
-        run: sbt -batch compileAll
+          languages: actions
       - name: CodeQL analyze
         uses: github/codeql-action/analyze@v4
       - name: TruffleHog secret scan