fix: ensure IPC file closed after use (#15194)

## Description

We fix a problem that caused IPC string files to evade proper context
management, leading to spurious ``ResourceWarning``s at runtime.

Fixes #15176.

Author: P403n1x87

ddtrace/internal/ipc.py

@@ -1,4 +1,3 @@
-from contextlib import contextmanager
 import os
 import secrets
 import tempfile
@@ -57,9 +56,7 @@ class ReadLock(BaseUnixLock):
     class WriteLock(BaseUnixLock):
         __acquire_mode__ = fcntl.LOCK_EX
 
-    @contextmanager
-    def open_file(path, mode):
-        yield unpatched_open(path, mode)
+    open_file = unpatched_open
 
 except ModuleNotFoundError:
     # Availability: Windows
@@ -78,7 +75,7 @@ def release(self):
 
     ReadLock = WriteLock = BaseWinLock  # type: ignore
 
-    def open_file(path, mode):
+    def open_file(path, mode):  # type: ignore
         import _winapi
 
         # force all modes to be read/write binary

releasenotes/notes/fix-ipc-open-file-ensure-closed-98d9707f56c416da.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Prevent a potential ``ResourceWarning`` in multiprocess scenarios.