fix: Prevent 'directory not empty' error in snowfakery on Linux (#3864)

Implemented potential fix to address Linux issue on #3859. Please advise
if any changes are requested.

---------

Co-authored-by: James Estevez <jestevez@salesforce.com>
Co-authored-by: James Estevez <j@jstvz.dev>
Co-authored-by: Bharath Chadarajupalli <vchadarajupalli@salesforce.com>

Author: 3 people

cumulusci/tasks/bulkdata/snowfakery.py

@@ -583,8 +583,10 @@ def _generate_and_load_initial_batch(self, working_directory: Path):
             self.sets_finished_while_generating_template = num_records
 
         new_template_dir = data_loader_new_directory_name(template_dir, self.run_until)
-        shutil.move(template_dir, new_template_dir)
-        template_dir = new_template_dir
+        # rename only if new_template_dir does not match template_dir
+        if template_dir.resolve() != new_template_dir.resolve():
+            shutil.move(template_dir, new_template_dir)
+            template_dir = new_template_dir
 
         # don't send data tables to child processes. All they
         # care about are ID->OID mappings