[3.7] bpo-32746: Fix multiple typos (GH-5144) (GH-5520)

Fix typos found by codespell in docs, docstrings, and comments.
(cherry picked from commit c3d9508ff22ece9a96892b628dd5813e2fb0cd80)

Co-authored-by: Leo Arias <leo.arias@canonical.com>
diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index a5cf687..e82425b 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -187,7 +187,7 @@
         return _is_coroutine(coro);
     }
 
-    /* either an error has occured or
+    /* either an error has occurred or
        type(coro) is in iscoroutine_typecache
     */
     return has_it;