ci: zephyr: fix Linux/Windows artifact comparison

Preserve the complete artifact suffix when deriving Linux artifact names
from Windows artifact names.

Fixes #11148

Signed-off-by: Piotr Hoppe <piotr.hoppe@intel.com>

Author: piotrhoppeintel

.github/workflows/zephyr.yml

@@ -511,7 +511,8 @@ jobs:
 
           set -x
           for windir in windows-build*; do
-            lindir=linux-"${windir#windows-}"
+            # Remove "windows-build" prefix and prepend "linux-build"
+            lindir="linux-build${windir#windows-build}"
             diff -qr "$lindir" "$windir" || : $((diffs++))
           done
           exit $diffs