Docs: remove incorrect GIL runtime flag requirement from glossary (GH-160661)

Docs: remove incorrect GIL runtime flag requirement from glossary (GH-160661)
(cherry picked from commit fbcc278)

Co-authored-by: Inada Naoki <songofacandy@gmail.com>

Author: miss-islington

Doc/glossary.rst

@@ -727,9 +727,7 @@ Glossary
       when doing I/O.
 
       As of Python 3.13, the GIL can be disabled using the :option:`--disable-gil`
-      build configuration. After building Python with this option, code must be
-      run with :option:`-X gil=0 <-X>` or after setting the :envvar:`PYTHON_GIL=0 <PYTHON_GIL>`
-      environment variable. This feature enables improved performance for
+      build configuration. This feature enables improved performance for
       multi-threaded applications and makes it easier to use multi-core CPUs
       efficiently. For more details, see :pep:`703`.