fix: Unregister semaphores from stdlib tracker immediately after creation

The previous fix attempted to unregister after loky's registration, but this
was too late. The semaphore is registered with stdlib tracker when _SemLock()
is created, so we must unregister immediately after creation in both code paths:
- In the loop when name=None (after line 79-81)
- When name is provided (after line 97)

This prevents 'leaked semaphore' warnings on Python 3.13+ while loky handles
cleanup properly through its own resource tracker.

Author: m0nas

loky/backend/synchronize.py

@@ -79,6 +79,14 @@ def __init__(self, kind, value, maxvalue, name=None):
                     self._semlock = _SemLock(
                         kind, value, maxvalue, SemLock._make_name(), unlink_now
                     )
+                    # FIX: Unregister from stdlib resource_tracker immediately after creation
+                    # to prevent "leaked semaphore" warnings on Python 3.13+
+                    if stdlib_resource_tracker is not None:
+                        try:
+                            stdlib_resource_tracker.unregister(self._semlock.name, "semlock")
+                        except (KeyError, ValueError):
+                            # Semaphore wasn't registered in stdlib tracker, that's fine
+                            pass
                 except FileExistsError:  # pragma: no cover
                     pass
                 else:
@@ -87,6 +95,14 @@ def __init__(self, kind, value, maxvalue, name=None):
                 raise FileExistsError("cannot find name for semaphore")
         else:
             self._semlock = _SemLock(kind, value, maxvalue, name, unlink_now)
+            # FIX: Unregister from stdlib resource_tracker immediately after creation
+            # to prevent "leaked semaphore" warnings on Python 3.13+
+            if stdlib_resource_tracker is not None:
+                try:
+                    stdlib_resource_tracker.unregister(self._semlock.name, "semlock")
+                except (KeyError, ValueError):
+                    # Semaphore wasn't registered in stdlib tracker, that's fine
+                    pass
         self.name = name
         util.debug(
             f"created semlock with handle {self._semlock.handle} and name "
@@ -104,15 +120,6 @@ def _after_fork(obj):
         # process shuts down we unlink the semaphore name
         resource_tracker.register(self._semlock.name, "semlock")
 
-        # FIX: Unregister from Python's stdlib resource_tracker to prevent
-        # "leaked semaphore" warnings on Python 3.13+, since loky handles cleanup
-        if stdlib_resource_tracker is not None:
-            try:
-                stdlib_resource_tracker.unregister(self._semlock.name, "semlock")
-            except (KeyError, ValueError):
-                # Semaphore wasn't registered in stdlib tracker, that's fine
-                pass
-
         util.Finalize(
             self, SemLock._cleanup, (self._semlock.name,), exitpriority=0
         )