fix pydoc.apropos and pydoc.synopsis on modules with empty docstrings (#21548)

Patch by Yuyang Guo and Berker Peksag.
diff --git a/Misc/ACKS b/Misc/ACKS
index 65518db..71f4048 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -506,6 +506,7 @@
 Dag Gruneau
 Filip GruszczyƄski
 Thomas Guettler
+Yuyang Guo
 Anuj Gupta
 Michael Guravage
 Lars Gustäbel
diff --git a/Misc/NEWS b/Misc/NEWS
index b453fe4..3f50594 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -13,6 +13,9 @@
 Library
 -------
 
+- Issue #21548: Fix pydoc.synopsis() and pydoc.apropos() on modules with empty
+  docstrings.
+
 - Issue #22885: Fixed arbitrary code execution vulnerability in the dbm.dumb
   module.  Original patch by Claudiu Popa.