Fix config tests: Make sure No core checkers are injected before testing config packages.

tests/config/conftest.py

@@ -14,6 +14,7 @@ import pytest
 from taipy.config._config import _Config
 from taipy.config._config_comparator._config_comparator import _ConfigComparator
 from taipy.config._serializer._toml_serializer import _TomlSerializer
+from taipy.config.checker._checker import _Checker
 from taipy.config.checker.issue_collector import IssueCollector
 from taipy.config.config import Config
 from taipy.config.section import Section
@@ -37,6 +38,8 @@ def reset_configuration_singleton():
     Config._collector = IssueCollector()
     Config._serializer = _TomlSerializer()
     Config._comparator = _ConfigComparator()
+    _Checker._checkers = []
+
 
 
 def register_test_sections():