Fix collection of short paths on Windows

Passing a short path in the command line was causing the matchparts check to fail, because ``Path(short_path) != Path(long_path)``.

Using ``os.path.samefile`` as fallback ensures the comparsion works on Windows when comparing short/long paths.

Fix #11895

changelog/11895.bugfix.rst

@@ -0,0 +1 @@
+Fix collection on Windows where initial paths contain the short version of a path (for example ``c:\PROGRA~1\tests``).

src/_pytest/main.py

@@ -901,6 +901,10 @@ class Session(nodes.Collector):
                     # Path part e.g. `/a/b/` in `/a/b/test_file.py::TestIt::test_it`.
                     if isinstance(matchparts[0], Path):
                         is_match = node.path == matchparts[0]
+                        if sys.platform == "win32" and not is_match:
+                            # In case the file paths do not match, fallback to samefile() to
+                            # account for short-paths on Windows (#11895).
+                            is_match = os.path.samefile(node.path, matchparts[0])
                     # Name part e.g. `TestIt` in `/a/b/test_file.py::TestIt::test_it`.
                     else:
                         # TODO: Remove parametrized workaround once collection structure contains