fix(pr_test_build_images): Use - instead of + for PR number

Author: Techassi

.github/workflows/pr_test_build_images.yaml

@@ -123,7 +123,7 @@ jobs:
           image-registry-username: github
           image-registry-password: ${{ secrets.NEXUS_PASSWORD }}
           image-repository: stackable/${{ env.PRODUCT_NAME }}
-          image-manifest-tag: ${{ steps.build.outputs.image-manifest-tag }}+pr${{ github.event.pull_request.number }}
+          image-manifest-tag: ${{ steps.build.outputs.image-manifest-tag }}-pr${{ github.event.pull_request.number }}
           source-image-uri: localhost/${{ env.PRODUCT_NAME }}:${{ steps.build.outputs.image-manifest-tag }}
 
       - name: Publish Container Image on oci.stackable.tech
@@ -133,7 +133,7 @@ jobs:
           image-registry-username: robot$sdp+github-action-build
           image-registry-password: ${{ secrets.HARBOR_ROBOT_SDP_GITHUB_ACTION_BUILD_SECRET }}
           image-repository: sdp/${{ env.PRODUCT_NAME }}
-          image-manifest-tag: ${{ steps.build.outputs.image-manifest-tag }}+pr${{ github.event.pull_request.number }}
+          image-manifest-tag: ${{ steps.build.outputs.image-manifest-tag }}-pr${{ github.event.pull_request.number }}
           source-image-uri: localhost/${{ env.PRODUCT_NAME }}:${{ steps.build.outputs.image-manifest-tag }}
 
   publish_manifests:
@@ -160,7 +160,7 @@ jobs:
           image-registry-username: github
           image-registry-password: ${{ secrets.NEXUS_PASSWORD }}
           image-repository: stackable/${{ env.PRODUCT_NAME }}
-          image-index-manifest-tag: ${{ env.PRODUCT_VERSION }}-stackable${{ env.SDP_VERSION }}+pr${{ github.event.pull_request.number }}
+          image-index-manifest-tag: ${{ env.PRODUCT_VERSION }}-stackable${{ env.SDP_VERSION }}-pr${{ github.event.pull_request.number }}
 
       - name: Publish and Sign Image Index Manifest to oci.stackable.tech
         uses: stackabletech/actions/publish-index-manifest@a3f7587879e9f12e04a29fd26435949aaa4fd59c # 0.2.0
@@ -169,4 +169,4 @@ jobs:
           image-registry-username: robot$sdp+github-action-build
           image-registry-password: ${{ secrets.HARBOR_ROBOT_SDP_GITHUB_ACTION_BUILD_SECRET }}
           image-repository: sdp/${{ env.PRODUCT_NAME }}
-          image-index-manifest-tag: ${{ env.PRODUCT_VERSION }}-stackable${{ env.SDP_VERSION }}+pr${{ github.event.pull_request.number }}
+          image-index-manifest-tag: ${{ env.PRODUCT_VERSION }}-stackable${{ env.SDP_VERSION }}-pr${{ github.event.pull_request.number }}