gh-101913: changed wording of docstring for _parsedate_tz (GH-134446)

Fixed incorrect word.
(cherry picked from commit f7e0fb6)

Co-authored-by: Gustaf <79180496+gostak-dd@users.noreply.github.com>
Co-authored-by: Gustaf <79180496+GGyll@users.noreply.github.com>

Author: gostak-dd

Lib/email/_parseaddr.py

@@ -59,7 +59,7 @@ def _parsedate_tz(data):
 
     The last (additional) element is the time zone offset in seconds, except if
     the timezone was specified as -0000.  In that case the last element is
-    None.  This indicates a UTC timestamp that explicitly declaims knowledge of
+    None.  This indicates a UTC timestamp that explicitly disclaims knowledge of
     the source timezone, as opposed to a +0000 timestamp that indicates the
     source timezone really was UTC.