[3.11] gh-101100: Fix datetime reference warnings (GH-114661) (GH-114718)

(cherry picked from commit e8b8f5e)

Co-authored-by: Skip Montanaro <[email protected]>

Author: serhiy-storchaka

Doc/conf.py

@@ -78,20 +78,25 @@
 nitpick_ignore = [
     # Standard C functions
     ('c:func', 'calloc'),
+    ('c:func', 'ctime'),
     ('c:func', 'dlopen'),
     ('c:func', 'exec'),
     ('c:func', 'fcntl'),
     ('c:func', 'fork'),
     ('c:func', 'free'),
+    ('c:func', 'gettimeofday'),
     ('c:func', 'gmtime'),
+    ('c:func', 'localeconv'),
     ('c:func', 'localtime'),
     ('c:func', 'main'),
     ('c:func', 'malloc'),
+    ('c:func', 'mktime'),
     ('c:func', 'printf'),
     ('c:func', 'realloc'),
     ('c:func', 'snprintf'),
     ('c:func', 'sprintf'),
     ('c:func', 'stat'),
+    ('c:func', 'strftime'),
     ('c:func', 'system'),
     ('c:func', 'vsnprintf'),
     # Standard C types