Add sbt/setup-sbt GitHub Actions

See https://github.com/sbt/setup-sbt/blob/75854e74d1300e4a4ec393739ca8633856901359/README.md#december-2024

Author: Atry

.github/workflows/scala.yml

@@ -27,6 +27,7 @@ jobs:
         with:
           java-version: "11"
           distribution: temurin
+      - uses: sbt/setup-sbt@v1
       - name: Cache SBT
         uses: actions/cache@v3
         with: