github: Update comments regarding tests and the pinned llvm version

.github/workflows/build.yml

@@ -332,8 +332,6 @@ jobs:
     # testing with the latest compiler instead of an older release).
     # Therefore, keep the test disabled by default; it's easy to enable
     # temporarily on a branch for testing.
-    # The libcxxabi and libunwind tests don't pass on the pinned 16.x branch,
-    # only on git main.
     if: false
     needs: [linux-cross-windows, prepare]
     runs-on: windows-latest
@@ -449,8 +447,7 @@ jobs:
   # Run the compiler-rt tests with the cross-built i686/x86_64 toolchains from
   # above. This also forces testing the bundled python executables.
   test-compiler-rt:
-    # These tests don't pass on the pinned 16.x branch, but only on latest
+    # Only running these tests in scheduled builds.
-    # git main - thus only run it for scheduled jobs.
     if: (github.event_name == 'schedule') && (github.repository == 'mstorsjo/llvm-mingw')
     needs: [linux-cross-windows, prepare]
     runs-on: windows-latest