config: move default interactive value to validate_config()

Per @ryneeverett's request, the value should be removed from the
schema.py. This breaks most of the tests, adding the `interactive =
False` to validate_config() fixes most of them. Some are still broken,
for which
#1193 was
created.

Author: Hi-Angel

bugwarrior/config/schema.py

@@ -138,7 +138,7 @@ class MainSectionConfig(BaseConfig):
 
     # added during configuration loading
     #: Interactive status.
-    interactive: bool = False
+    interactive: bool
 
     @computed_field
     @property

tests/config/test_validation.py

@@ -10,7 +10,7 @@ class TestValidation(ConfigTest):
     def setUp(self):
         super().setUp()
         self.config = {
-            'general': {'targets': ['my_service', 'my_kan', 'my_gitlab']},
+            'general': {'targets': ['my_service', 'my_kan', 'my_gitlab'], 'interactive': False},
             'my_service': {
                 'service': 'github',
                 'login': 'ralph',