better logic to pick up snapshot/local version

.github/workflows/native-image-tests.yml

@@ -35,9 +35,11 @@ jobs:
           jvm: temurin:1.11
 
       - name: Gather version
+        # some cleanup of the sbt output to get the version sbt will use when publishing below
         run: |-
-          echo `git describe --tags | sed -e "s/v\(.*\)-\([0-9][0-9]*\).*/\\1+\\2-/"``git rev-parse HEAD | head -c8`-SNAPSHOT > ~/.version
-          cat ~/.version
+          sbt "akka-management/version" --batch --no-colors | tail -n 1 | cut -f 2 -d ' ' | tr -d '\n' > ~/.version
+          echo [$(cat ~/.version)]
+          # useful for debugging: hexdump -c ~/.version
 
       - name: Publish artifacts locally
         run: |-