Fix GiHub action change (missing sbt)

Author: schoeberl

.github/workflows/scala.yml

@@ -21,7 +21,8 @@ jobs:
       with:
         java-version: '11'
         distribution: 'temurin'
-        cache: 'sbt'
+    - name: Setup sbt
+    uses: sbt/setup-sbt@v1
     - name: Setup Verilator
       run: sudo apt-get install verilator
     - name: Run tests