Run lint workflow on all PRs to fix stuck required checks

The lint workflow was path-filtered to source files, so PRs that didn't
touch them never ran clang-format/cmake-format. Since those checks are
required, such PRs were blocked forever waiting for a status that never
came. Drop the paths filter so the workflow always reports a status.

.github/workflows/lint.yml

@@ -2,11 +2,6 @@ name: lint
 
 on:
   pull_request:
-    paths:
-      - '**.h'
-      - '**.cc'
-      - '**.cmake'
-      - '**/CMakeLists.txt'
 
 permissions:
   contents: read