add monthly release

.github/workflows/tag-monthly.yml

@@ -0,0 +1,29 @@
+name: tag-monthly
+on:
+  schedule:
+    - cron: '0 2 1 * *'
+
+env:
+  GO_VERSION: 1.18
+
+jobs:
+  release:
+    name: tag-monthly
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+          ref: master
+      - uses: actions/setup-go@v3
+        with:
+          go-version: ${{ env.GO_VERSION }}
+          check-latest: true
+      - uses: actions/cache@v3
+        if: ${{ !env.ACT }}
+        with:
+          path: ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+      - run: make promote