update CI to use protobuf 4.x (#396)

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

Author: davidzhao

.github/workflows/build-protocol.yml

@@ -36,7 +36,7 @@ jobs:
       - uses: actions/setup-python@v4
 
       - name: Install Protoc
-        uses: arduino/setup-protoc@v2
+        uses: arduino/setup-protoc@v3
         with:
           version: "25.1"
           repo-token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/build-rtc.yml

@@ -38,12 +38,12 @@ jobs:
       - name: Install Protoc
         uses: arduino/setup-protoc@v3
         with:
-          version: "26.x"
+          version: "25.1"
           repo-token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Install deps
         run: |
-          pip3 install mypy-protobuf==3.6.0
+          pip3 install mypy-protobuf==3.6.0 "protobuf>=4.25.0,<5.0.0"
 
       - name: generate python stubs
         run: ./generate_proto.sh