[mod] pylint all files with one profile / drop PYLINT_SEARXNG_DISABLE_OPTION

In the past, some files were tested with the standard profile, others with a
profile in which most of the messages were switched off ... some files were not
checked at all.

- ``PYLINT_SEARXNG_DISABLE_OPTION`` has been abolished
- the distinction ``# lint: pylint`` is no longer necessary
- the pylint tasks have been reduced from three to two

  1. ./searx/engines -> lint engines with additional builtins
  2. ./searx ./searxng_extra ./tests -> lint all other python files

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/external_urls.py

@@ -1,3 +1,6 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# pylint: disable=missing-module-docstring
+
 import math
 
 from searx.data import EXTERNAL_URLS
@@ -46,8 +49,7 @@ def get_external_url(url_id, item_id, alternative="default"):
         if url_template is not None:
             if item_id is not None:
                 return url_template.replace('$1', item_id)
-            else:
-                return url_template
+            return url_template
     return None