scalaVersion seems to be a predefined key. Try passing in to sbt scri…

…pt but allow default

.github/workflows/ci.yaml

@@ -56,14 +56,14 @@ jobs:
         uses: sbt/setup-sbt@v1
 
       - name: Echo config versions
-        run: >
+        run: |
           java -version
           echo Scala version: $SCALA_VERSION
           echo Spark version: $SPARK_VERSION
 
       - name: Build and test
         run: >
-          sbt --batch clean test
+          sbt ++$SCALA_VEERSION --batch clean test
 
 # Architecture options: x86, x64, armv7, aarch64, ppc64le
 # setup-java@v4 has a "with cache" option

build.sbt

@@ -28,7 +28,6 @@ description := "The Apache DataSketches package for Spark"
 
 licenses += ("Apache-2.0", url("http://www.apache.org/licenses/LICENSE-2.0"))
 
-val scalaVersion = settingKey[String]("The version of Scala")
 scalaVersion := sys.env.getOrElse("SCALA_VERSION", DEFAULT_SCALA_VERSION)
 
 val sparkVersion = settingKey[String]("The version of Spark")