feat: use Repository variables save docker hub info

Author: geekwho-eth

.github/workflows/bitcoin_core.yaml

@@ -14,8 +14,6 @@ jobs:
   build:
     runs-on: ubuntu-latest
     # use strategy matrix build images
-    env:
-      DOCKERHUB_REPO: "bitcoin-core"
     strategy:
       matrix:
         image:
@@ -63,12 +61,12 @@ jobs:
       - name: Login to Docker Hub
         uses: docker/login-action@v3
         with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          username: ${{ vars.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       - name: Build and push
         uses: docker/build-push-action@v5
         with:
           context: ${{ matrix.image.context }}
           platforms: linux/amd64,linux/arm64
           push: true
-          tags: ${{ secrets.DOCKERHUB_USERNAME }}/${{ env.DOCKERHUB_REPO }}:${{ matrix.image.name }}
+          tags: ${{ vars.DOCKERHUB_USERNAME }}/${{ vars.DOCKERHUB_REPO }}:${{ matrix.image.name }}