fix: handle symlink to file change on delta update

- When upgrading from GE-Proton9-23 to GE-Proton9-24, the link file 'umu-356190.py' became a real file. As a result, a NotImplementedError would be raised when changing the file perms of the source file to be executable, resulting in an incomplete upgrade where that file would be missing. In these cases, the patcher needs to delete the link and insert the data on update.

umu/umu_bspatch.py

@@ -260,6 +260,12 @@ def _patch_proton_file(self, path: Path, item: Entry) -> None:
         mode: int = item["mode"]
         size: int = item["size"]
 
+        if (item["type"] == FileType.File.value) and path.is_symlink():
+            path.unlink(missing_ok=True)
+            path.write_bytes(bdiff)
+            path.chmod(mode, follow_symlinks=False)
+            return
+
         try:
             # Since some wine binaries are missing the writable bit and
             # we're memory mapping files. Before applying a binary patch,