# What this PR does
```bash
❯ mypy .
Success: no issues found in 595 source files
```
- re-enable the mypy CI check
- fixes all `django-manager-missing` mypy errors
- disable all other rules currently giving mypy errors
- changing the approach here. rather than enforcing that backend
contributors fix >= 1 `mypy` error on their PR, lets simply disable all
the rules that're currently returning errors and slowly re-enable these
one at a time #2392
## Checklist
- [ ] Unit, integration, and e2e (if applicable) tests updated (N/A)
- [ ] Documentation added (or `pr:no public docs` PR label added if not
required) (N/A)
- [ ] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required) (N/A)
# What this PR does
Handle different failing authentication scenarios (e.g. when token is
invalid or instance context is not a valid JSON) so endpoints return
appropriate response code (401 instead of 500).
## Which issue(s) this PR fixes
Related to https://github.com/grafana/oncall-private/issues/1633
## Checklist
- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)
