fix: don't check BCR patches on Windows

The patches aren't platform-specific so it's redundant to test on windows.
Also our shell one-liner doesn't work on windows.

.github/workflows/bazel.yaml

@@ -134,7 +134,7 @@ jobs:
 
       # See https://github.com/bazel-contrib/publish-to-bcr#including-patches
       - name: verify bcr patches
-        if: matrix.bzlmodEnabled && hashFiles('.bcr/patches/*.patch') != ''
+        if: matrix.bzlmodEnabled && hashFiles('.bcr/patches/*.patch') != '' && ! startsWith(matrix.os, 'windows')
         run: patch --dry-run -p1 < .bcr/patches/*.patch
 
       - name: Test