Print Java version in release-verify-signatures workflow

Author: emlun

.github/workflows/release-verify-signatures.yml

@@ -23,7 +23,9 @@ jobs:
         java-version: ${{ matrix.java }}
 
     - name: Build jars
-      run: ./gradlew jar
+      run: |
+        java --version
+        ./gradlew jar
 
     - name: Fetch keys
       run: gpg --no-default-keyring --keyring yubico --keyserver hkps://keys.openpgp.org --recv-keys 57A9DEED4C6D962A923BB691816F3ED99921835E