[build] Upgrade clang-format and clang-tidy (NFC) (#3422)

.github/workflows/lint-format.yml

@@ -22,17 +22,17 @@ jobs:
         with:
           python-version: 3.8
       - name: Install clang-format
-        run: sudo apt-get update -q && sudo apt-get install -y clang-format-10
+        run: sudo apt-get update -q && sudo apt-get install -y clang-format-12
       - name: Install wpiformat
         run: pip3 install wpiformat
       - name: Run
-        run: wpiformat -clang 10
+        run: wpiformat -clang 12
       - name: Check Output
         run: git --no-pager diff --exit-code HEAD
   tidy:
     name: "clang-tidy"
     runs-on: ubuntu-latest
-    container: wpilib/roborio-cross-ubuntu:2020-20.04
+    container: wpilib/roborio-cross-ubuntu:2021-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Fetch all history and metadata
@@ -40,8 +40,16 @@ jobs:
           git fetch --prune --unshallow
           git checkout -b pr
           git branch -f main origin/main
-      - name: Install clang-format and clang-tidy
-        run: sudo apt-get update -q && sudo apt-get install -y clang-format-10 clang-tidy-10 python3.8
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Install clang-tidy
+        run: |
+          wget https://apt.llvm.org/llvm.sh
+          chmod +x llvm.sh
+          sudo ./llvm.sh 12
+          sudo apt-get install -y clang-tidy-12
       - name: Install wpiformat
         run: pip3 install wpiformat
       - name: Create compile_commands.json
@@ -49,4 +57,4 @@ jobs:
       - name: List changed files
         run: wpiformat -list-changed-files
       - name: Run clang-tidy
-        run: wpiformat -clang 10 -no-format -tidy-changed -compile-commands=build-cmake
+        run: wpiformat -clang 12 -no-format -tidy-changed -compile-commands=build-cmake