[llvm] [libc][workflow] improve ci coverage with windows-2025 and arm ubuntu (PR #123745)

[Nick Desaulniers via llvm-commits]

================
@@ -11,12 +11,18 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-24.04
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         include:
-          - c_compiler: clang
+          - os: ubuntu-24.04
+            ccache-variant: sccache
----------------
nickdesaulniers wrote:

Please add a comment linking to that issue in the yml file. I assume it will be resolved some day, so if someone notices that in the future, it would be good to then resolve the arm specific differences.

https://github.com/llvm/llvm-project/pull/123745