ci: Update Github Actions workflows (#9774)

.github/workflows/cpp_lint.yml

@@ -30,19 +30,20 @@ jobs:
       - uses: actions/checkout@v2
       - name: Install clang-format
         run: |
-          sudo apt-get install ${CLANG_FORMAT} -qyy
-        env:
-          CLANG_FORMAT: clang-format-9
+          sudo apt-get install clang-format-9 -qyy
+
       - name: Run clang-format
         run: |
           source ./util/ci/lint.sh
           perform_lint
+        env:
+          CLANG_FORMAT: clang-format-9
 
   clang_tidy:
     runs-on: ubuntu-18.04
     steps:
     - uses: actions/checkout@v2
-    - name: Install clang-tidy
+    - name: Install deps
       run: |
         sudo apt-get install clang-tidy-9 -qyy
         source ./util/ci/common.sh