ci: only run when applicable (#4752)

- only run tests when .go, .mod, .sum files have been touched
- only run proto checks when .proto files have been touched

Signed-off-by: Marko Baricevic marbar3778@yahoo.com

.github/workflows/proto.yml

@@ -5,8 +5,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@master
-      - uses: docker-practice/actions-setup-docker@master
+      - uses: technote-space/get-diff-action@v1
+        id: git_diff
+        with:
+          SUFFIX_FILTER: .proto
+          SET_ENV_NAME_INSERTIONS: 1
+          SET_ENV_NAME_LINES: 1
       - name: lint
         run: make proto-lint
+        if: "env.GIT_DIFF != ''"
       - name: check-breakage
         run: make proto-check-breaking-ci
+        if: "env.GIT_DIFF != ''"