added a github workflow file

.github/workflows/build.yml

@@ -0,0 +1,20 @@
+name: Build Hawk
+
+on:
+  push:
+
+jobs:
+  build-rocky9:
+    runs-on: docker.io/hyunghwan/dev:gcc.rocky9
+    steps:
+      - name: Manual checkout
+        run: |
+          git config --global --add safe.directory "$GITHUB_WORKSPACE"
+          git fetch --no-tags --depth=1 origin ${GITHUB_REF:-main}
+          git checkout ${GITHUB_REF:-main}
+
+      - name: Run build
+        run: |
+          find . -exec touch -r {} +
+          mkdir -p bld/rocky9 && cd bld/rocky9
+          ../../configure && make && make check && make rpm