ci: add Gitea Actions workflows

Add ci.yml (test, lint, benchmark) and release.yml (cross-compile
builds) compatible with Gitea Actions. Uses upload-artifact@v3
instead of v4 which is unsupported on Gitea.

.gitea/workflows/ci.yml

@@ -0,0 +1,79 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  GO_VERSION: "1.24"
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Verify dependencies
+        run: go mod verify
+
+      - name: Build
+        run: go build -v ./...
+
+      - name: Run go vet
+        run: go vet ./...
+
+      - name: Run tests
+        run: go test -v -race ./...
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Check formatting
+        run: |
+          if [ "$(gofmt -s -l . | wc -l)" -gt 0 ]; then
+            echo "The following files are not formatted properly:"
+            gofmt -s -l .
+            exit 1
+          fi
+
+      - name: Install staticcheck
+        run: go install honnef.co/go/tools/cmd/staticcheck@latest
+
+      - name: Run staticcheck
+        run: staticcheck ./...
+
+  benchmark:
+    name: Benchmark
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Run benchmarks
+        run: go test -bench=. -benchmem -count=1 ./...

.gitea/workflows/release.yml

@@ -0,0 +1,79 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+env:
+  GO_VERSION: "1.24"
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Run tests
+        run: go test -race ./...
+
+      - name: Run go vet
+        run: go vet ./...
+
+  build:
+    name: Build (${{ matrix.goos }}, ${{ matrix.goarch }})
+    needs: test
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - goos: linux
+            goarch: amd64
+            suffix: ""
+          - goos: linux
+            goarch: arm64
+            suffix: ""
+          - goos: darwin
+            goarch: amd64
+            suffix: ""
+          - goos: darwin
+            goarch: arm64
+            suffix: ""
+          - goos: windows
+            goarch: amd64
+            suffix: ".exe"
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Build binary
+        env:
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+        run: |
+          VERSION=${GITHUB_REF#refs/tags/}
+          COMMIT=$(git rev-parse --short HEAD)
+          DATE=$(date -u +%Y-%m-%dT%H:%M:%SZ)
+          LDFLAGS="-s -w -X main.Version=$VERSION -X main.Commit=$COMMIT -X main.BuildDate=$DATE"
+          mkdir -p dist
+          go build -ldflags "$LDFLAGS" -o "dist/jdenticon-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.suffix }}" ./cmd/jdenticon/
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: jdenticon-${{ matrix.goos }}-${{ matrix.goarch }}
+          path: dist/