Don't explicitly install clang-format.

It's failing on Ubuntu 24.04, and probably (?) isn't needed anyway.

.github/workflows/build.yml

@@ -7,8 +7,6 @@ jobs:
     steps:
       - name: Check out repository code
         uses: actions/checkout@v4
-      - name: Install clang-format
-        run: pip install clang-format
       - name: Check source formatting
         run: |
           find native~/Runtime native~/Editor native~/Shared \( -iname '*.cpp' -o -iname '*.h' \) -print0 | xargs -0 clang-format --dry-run -Werror