prevent some jobs running from forked repository

Signed-off-by: zhzhuang-zju <m17799853869@163.com>

.github/workflows/dockerhub-released-chart.yml

@@ -9,6 +9,10 @@ jobs:
   publish-chart-to-dockerhub:
     name: publish to DockerHub
     runs-on: ubuntu-22.04
+    # prevent job running from forked repository, otherwise
+    # 1. running on the forked repository would fail as missing necessary secret.
+    # 2. running on the forked repository would use unnecessary GitHub Action time.
+    if: ${{ github.repository == 'karmada-io/karmada' }}
     steps:
       - name: checkout code
         uses: actions/checkout@v4

.github/workflows/dockerhub-released-image.yml

@@ -8,6 +8,10 @@ permissions:
 jobs:
   publish-image-to-dockerhub:
     name: publish to DockerHub
+    # prevent job running from forked repository, otherwise
+    # 1. running on the forked repository would fail as missing necessary secret.
+    # 2. running on the forked repository would use unnecessary GitHub Action time.
+    if: ${{ github.repository == 'karmada-io/karmada' }}
     permissions:
       id-token: write # To be able to get OIDC ID token to sign images.
     strategy:

.github/workflows/release.yml

@@ -206,6 +206,10 @@ jobs:
       GH_TOKEN: ${{ github.token }}
     needs: 
     - release-assests
+    # prevent job running from forked repository, otherwise
+    # 1. running on the forked repository would use unnecessary GitHub Action time.
+    # 2. running on the forked repository would open a PR to publish an inaccurate version of karmada in repo kubernetes-sigs/krew-index.
+    if: ${{ github.repository == 'karmada-io/karmada' }}
     name: Update krew-index
     runs-on: ubuntu-22.04
     steps: