Do not serialize raw Action objects and their callable (fixes #136, #137)

[leplatrem]

Fixes #137
Fixes #136

I could reproduce these issues by:

• setting up real clients (Bugzilla API key, JIRA API key) in .env
• running locally with make start
• checking that clients can connect with http :8000/__heartbeat__

In order to force initialization of actions on the /whiteboard_tags/ endpoint I added this:

 app.include_router(monitor_router)
@@ -109,6 +110,9 @@ def get_whiteboard_tags(
     actions: Actions = Depends(configuration.get_actions),
 ):
     """API for viewing whiteboard_tags and associated data"""
+    for action in actions:
+        assert callable(action.callable)  # will load Python module
+

And then, reaching out /whiteboard_tags/ would crash, trying to serialize:

1. the action executor class (callable attribute)
2. the bugzilla client
3. some internal requests/pool/socket object

I could only fix it by using .dict(exclude={"callable"}) (or using model config and just .dict() as in the present patch)

I failed at reproducing the situation in a unit test (naive version below):

+def test_whiteboard_tags_with_initialized_actions(
+    anon_client, mocked_jira, webhook_create_example
+):
+    assert configuration.get_actions(), "There is at least one configured action"
+    for action in configuration.get_actions():
+        action.callable(webhook_create_example)
+
+    resp = anon_client.get("/whiteboard_tags/")
+    assert resp.status_code == 200  # not crashing :)
+

because the issue comes from an internal urlib object that only gets initialized when session is established

[grahamalama]

Reproduced and verified this fix locally.

We should add an issue to reproduce this through a test (and I still think this can all be done through straight model config), but in the interest of getting this bug fixed, let's get this shipped.