CI: run gradle commands in separate steps

right now `./gradlew build` could fail but the script would still go on
(because neither `set -e` is set nor `&&` is used to run both commands
together).

running it in two steps gives more visibilty to which step is failing.
note that `publishPluginZipPublicationToZipStagingRepository` is tested
explicitly to ensure that this step works as it has previously failed.

fixes #60

Signed-off-by: Ralph Ursprung <[email protected]>

.github/workflows/CI.yml

@@ -29,9 +29,9 @@ jobs:
       with:
         java-version: ${{ matrix.java }}
         distribution: temurin
-
     - name: Build and Run Tests
       run: |
-          ./gradlew build
-           # Generated by 'opensearch.pluginzip' custom gradle plugin
-          ./gradlew publishPluginZipPublicationToZipStagingRepository
+        ./gradlew build
+    - name: Publish plugin ZIP to staging repository
+      run: |
+        ./gradlew publishPluginZipPublicationToZipStagingRepository