Fix test failures on Windows

`_get_prof_file_name` did not work correctly when the file separator
was not `/`.

project/tests/test_collector.py

@@ -1,4 +1,5 @@
 import cProfile
+import os.path
 import sys
 
 from django.test import TestCase
@@ -95,5 +96,5 @@ def _get_prof_file_name(cls, request_path: str) -> str:
         DataCollector().configure(request)
         DataCollector().finalise()
         file_path = DataCollector().request.prof_file.name
-        filename = file_path.rsplit('/')[-1]
+        filename = os.path.basename(file_path)
         return filename.replace(f"{request.id}.prof", "")