Merge #381: Use normal variables instead of secrets for user and `r…

…epo` on DockerHub

b93564c fix: [#362] rename docker image (Jose Celano)

Pull request description:

  From: `torrust/index-backend:develop`
  To: `torrust/index:develop`

ACKs for top commit:
  josecelano:
    ACK b93564c

Tree-SHA512: 26162169d66b0e35a81619c359dd62f8aac68296102d641928151876b7a5a0eaf8fb02d0f479e07ffd3e2a6f4525322285e07f2f3406e61d9a27a99f34b58581

.github/workflows/container.yaml

@@ -111,15 +111,15 @@ jobs:
         uses: docker/metadata-action@v5
         with:
           images: |
-            "${{ secrets.DOCKER_HUB_USERNAME }}/${{secrets.DOCKER_HUB_REPOSITORY_NAME }}"
+            "${{ vars.DOCKER_HUB_USERNAME }}/${{vars.DOCKER_HUB_REPOSITORY_NAME }}"
           tags: |
             type=ref,event=branch
 
       - id: login
         name: Login to Docker Hub
         uses: docker/login-action@v3
         with:
-          username: ${{ secrets.DOCKER_HUB_USERNAME }}
+          username: ${{ vars.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
 
       - id: setup
@@ -149,7 +149,7 @@ jobs:
         uses: docker/metadata-action@v5
         with:
           images: |
-            "${{ secrets.DOCKER_HUB_USERNAME }}/${{secrets.DOCKER_HUB_REPOSITORY_NAME }}"
+            "${{ vars.DOCKER_HUB_USERNAME }}/${{vars.DOCKER_HUB_REPOSITORY_NAME }}"
           tags: |
             type=semver,value=${{ needs.context.outputs.version }},pattern={{raw}}
             type=semver,value=${{ needs.context.outputs.version }},pattern={{version}}
@@ -160,7 +160,7 @@ jobs:
         name: Login to Docker Hub
         uses: docker/login-action@v3
         with:
-          username: ${{ secrets.DOCKER_HUB_USERNAME }}
+          username: ${{ vars.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
 
       - id: setup