[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>

searxng_extra/docs_prebuild

@@ -1,7 +1,5 @@
 #!/usr/bin/env python
-# lint: pylint
 # SPDX-License-Identifier: AGPL-3.0-or-later
-
 """Script that implements some prebuild tasks needed by target docs.prebuild
 """
 
@@ -9,10 +7,10 @@ import sys
 import os.path
 import time
 from contextlib import contextmanager
+
 from searx import settings, get_setting, locales
 from searx.infopage import InfoPageSet, InfoPage
 
-
 _doc_user = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'docs', 'user'))
 
 
@@ -27,13 +25,13 @@ def main():
     with infopageset_ctx as infopageset:
         for _, _, page in infopageset.iter_pages('en'):
             fname = os.path.join(_doc_user, os.path.basename(page.fname))
-            with open(fname, 'w') as f:
+            with open(fname, 'w', encoding='utf-8') as f:
                 f.write(page.content)
 
 
-class OfflinePage(InfoPage):
+class OfflinePage(InfoPage):  # pylint: disable=missing-class-docstring
 
-    def get_ctx(self):  # pylint: disable=no-self-use
+    def get_ctx(self):
         """Jinja context to render :py:obj:`DocPage.content` for offline purpose (no
         links to SearXNG instance)"""
 
@@ -55,7 +53,7 @@ def _instance_infosetset_ctx(base_url):
     # registered in the Flask app.
 
     settings['server']['secret_key'] = ''
-    from searx.webapp import app
+    from searx.webapp import app  # pylint: disable=import-outside-toplevel
 
     # Specify base_url so that url_for() works for base_urls.  If base_url is
     # specified, then these values from are given preference over any Flask's