chore: refactor build process and repository cleanup

- Introduce Go setup and caching in Docker GitHub Actions workflow
- Add `release` directory to `.gitignore`
- Remove `main.go` file from the repository

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

.gitea/workflows/docker.yml

@@ -24,6 +24,33 @@ jobs:
         with:
           fetch-depth: 0 # all history for all branches and tags
 
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          check-latest: true
+
+      - uses: https://gitea.com/actions/go-hashfiles@v0.0.1
+        id: hash-go
+        with:
+          patterns: |
+            go.mod
+            go.sum
+      - name: cache go
+        id: cache-go
+        uses: https://github.com/actions/cache@v3
+        with:
+          path: |
+            /go_path
+            /go_cache
+          key: go_path-${{ steps.hash-go.outputs.hash }
+
+      - name: Build binary
+        env:
+          TAGS: ""
+        run: |
+          make docker-build-linux-amd64
+          make docker-build-linux-arm64
+
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v2