CHORE(ci): migrate from GHCR to Zot registry

- Change registry from ghcr.io to zot0213.kro.kr
- Update secrets to ZOT_USERNAME and ZOT_PASSWORD
- Simplify image name to docusaurus

.github/workflows/build.yml

@@ -8,8 +8,8 @@ on:
   workflow_dispatch:
 
 env:
-  REGISTRY: ghcr.io
-  IMAGE_NAME: ${{ github.repository }}
+  REGISTRY: zot0213.kro.kr
+  IMAGE_NAME: docusaurus
 
 jobs:
   build-and-push:
@@ -29,23 +29,18 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
-      - name: Log in to GitHub Container Registry
+      - name: Log in to Zot Registry
         uses: docker/login-action@v3
         with:
           registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.CR_PAT }}
-
-      - name: Lowercase repository name
-        id: lowercase
-        run: |
-          echo "repo=$(echo ${{ github.repository }} | tr '[:upper:]' '[:lower:]')" >> $GITHUB_OUTPUT
+          username: ${{ secrets.ZOT_USERNAME }}
+          password: ${{ secrets.ZOT_PASSWORD }}
 
       - name: Extract metadata (tags, labels)
         id: meta
         uses: docker/metadata-action@v5
         with:
-          images: ${{ env.REGISTRY }}/${{ steps.lowercase.outputs.repo }}
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |
             type=sha,prefix=sha-,format=long
             type=raw,value=latest,enable={{is_default_branch}}
@@ -58,9 +53,6 @@ jobs:
         with:
           context: .
           file: ./Dockerfile
-          build-contexts: |
-            docusaurus=./docusaurus
-            nginx=./nginx
           push: true
           platforms: linux/arm64
           tags: ${{ steps.meta.outputs.tags }}