goipgrep: refactor into module; pure-Go ping/resolve; cache+CI; drop binary

projects/go-tools/go/goipgrep/.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: ci
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+      - name: go test (linux)
+        if: matrix.os == 'ubuntu-latest'
+        run: go test ./...
+      - name: go test (macos)
+        if: matrix.os == 'macos-latest'
+        run: go test -ldflags='-linkmode=external' ./...
+      - run: go vet ./...
+      - run: ./scripts/build.sh