[#320] .forgejo: Add generate-proto action

Signed-off-by: Alexander Chuprov <a.chuprov@yadro.com>

.forgejo/workflows/codegen.yml

@@ -0,0 +1,22 @@
+name: Code generation
+on: [pull_request]
+
+jobs:
+  wrappers:
+    name: Generate proto
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: '1.23'
+      - name: Generate proto
+        run: make protoc
+      # The command seems to be non-deterministic.
+      # However, with >20 runs I haven't been able to reproduce the issue.
+      # This `git diff` is here to print diff in case we catch the behaviour again.
+      - name: Print diff
+        run: git diff HEAD
+      - name: Check that nothing has changed
+        run: git diff-index --exit-code HEAD