fixing broken check mode in the github_key (#9186)

* fixing datetime.strftime()

* added changelog fragment

* Update changelogs/fragments/9186-fix-broken-check-mode-in-github-key.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

---------

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/9186-fix-broken-check-mode-in-github-key.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - github_key - in check mode, a faulty call to ```datetime.strftime(...)``` was being made which generated an exception (https://github.com/ansible-collections/community.general/issues/9185).

plugins/modules/github_key.py

@@ -162,7 +162,7 @@ def create_key(session, name, pubkey, check_mode):
             'key': pubkey,
             'title': name,
             'url': 'http://example.com/CHECK_MODE_GITHUB_KEY',
-            'created_at': datetime.strftime(now_t, '%Y-%m-%dT%H:%M:%SZ'),
+            'created_at': datetime.datetime.strftime(now_t, '%Y-%m-%dT%H:%M:%SZ'),
             'read_only': False,
             'verified': False
         }