bpo-18372: Add missing PyObject_GC_Track() calls in the pickle module (GH-8505)

(cherry picked from commit 359bd4f61b9e1493081f4f67882554247b53926a)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 15e15cd..c8b3ef7 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1114,6 +1114,8 @@
         Py_DECREF(self);
         return NULL;
     }
+
+    PyObject_GC_Track(self);
     return self;
 }
 
@@ -1491,6 +1493,7 @@
         return NULL;
     }
 
+    PyObject_GC_Track(self);
     return self;
 }