fix: Remove Docker buildx setup to resolve CI/CD permissions error

Issue:
- Docker buildx creates containerized builder requiring elevated capabilities
- Gitea Actions runner doesn't have permission to apply Linux capabilities
- Error: "unable to apply caps: operation not permitted"

Solution:
- Removed docker/setup-buildx-action from both build jobs
- Using standard docker build (already configured via DOCKER_BUILDKIT=1)
- BuildKit features still enabled via environment variable

Impact:
- CI/CD builds will now succeed without capability errors
- No functionality lost (workflow uses 'docker build', not 'docker buildx build')
- Faster build start (no buildx container creation overhead)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.gitea/workflows/build-and-deploy.yml

@@ -21,9 +21,6 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-
       - name: Build LittleShop image
         run: |
           echo "Building LittleShop Docker image"
@@ -54,9 +51,6 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-
       - name: Build TeleBot image
         run: |
           echo "Building TeleBot Docker image"