Skip sphinx.locale.init_console when running tests (#11159)

Tests for Sphinx's CLIs, like test_apidoc, indirectly init_console to
initialize translations for Sphinx's console domain, the one with
Sphinx's log messages. This bleeds over subsequent tests by making
warnings translated. Fix this by skipping init_console when running
Sphinx's test suite.

tests/conftest.py

@@ -5,9 +5,23 @@
 import pytest
 
 import sphinx
+import sphinx.locale
 from sphinx.testing import comparer
 from sphinx.testing.path import path
 
+
+def _init_console(locale_dir=sphinx.locale._LOCALE_DIR, catalog='sphinx'):
+    """Monkeypatch ``init_console`` to skip its action.
+
+    Some tests rely on warning messages in English. We don't want
+    CLI tests to bleed over those tests and make their warnings
+    translated.
+    """
+    return sphinx.locale.NullTranslations(), False
+
+
+sphinx.locale.init_console = _init_console
+
 pytest_plugins = 'sphinx.testing.fixtures'
 
 # Exclude 'roots' dirs for pytest test collector