fix: clean up target path upon storage in order to avoid merges of di…

…rectories (#25)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Enhanced the storage process with a cleanup procedure, ensuring a
clean state before storing new data.
- **Improvements**
- Improved robustness by effectively managing both directory and file
scenarios during cleanup, preventing conflicts from residual data.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

snakemake_storage_plugin_fs/__init__.py

@@ -206,8 +206,15 @@ def retrieve_object(self):
 
     def store_object(self):
         # Ensure that the object is stored at the location specified by
-        # self.local_path().
-        self.query_path.parent.mkdir(exist_ok=True, parents=True)
+        # self.query_path.
+        if self.query_path.exists():
+            # Clean up the target path
+            if self.query_path.is_dir():
+                shutil.rmtree(self.query_path, ignore_errors=True)
+            else:
+                self.query_path.unlink(missing_ok=True)
+        else:
+            self.query_path.parent.mkdir(exist_ok=True, parents=True)
         # We want to respect the permissions in the target folder, in particular the
         # setgid bit. Hence, we use --no-p to avoid preserving of permissions from the
         # source to the target.