Cleanup: Strict compiler warning

A static function is only used from asserts, generating unused
warning for release builds.

Pull Request: https://projects.blender.org/blender/blender/pulls/117398

source/blender/blenlib/intern/fileops_c.cc

@@ -857,7 +857,7 @@ enum {
 
 typedef int (*RecursiveOp_Callback)(const char *from, const char *to);
 
-static bool path_has_trailing_slash(const char *path)
+[[maybe_unused]] static bool path_has_trailing_slash(const char *path)
 {
   const int path_len = strlen(path);
   if (path_len == 0) {