Closes issue #22791: Improved datetime from timestamp methods documentation.

Original patch by Akira Li.
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index 701c587..09285d9 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -5020,8 +5020,7 @@
 
     {"utcfromtimestamp", (PyCFunction)datetime_utcfromtimestamp,
      METH_VARARGS | METH_CLASS,
-     PyDoc_STR("timestamp -> UTC datetime from a POSIX timestamp "
-               "(like time.time()).")},
+     PyDoc_STR("Construct a naive UTC datetime from a POSIX timestamp.")},
 
     {"strptime", (PyCFunction)datetime_strptime,
      METH_VARARGS | METH_CLASS,