* Perfer `type(x) is int` to `isinstance(x, int)`
This covered all additional instances I could see where `x` was
user-controlled.
The remaining cases are
```
$ rg -s 'isinstance.*[^_]int'
tests/replication/_base.py
576: if isinstance(obj, int):
synapse/util/caches/stream_change_cache.py
136: assert isinstance(stream_pos, int)
214: assert isinstance(stream_pos, int)
246: assert isinstance(stream_pos, int)
267: assert isinstance(stream_pos, int)
synapse/replication/tcp/external_cache.py
133: if isinstance(result, int):
synapse/metrics/__init__.py
100: if isinstance(calls, (int, float)):
synapse/handlers/appservice.py
262: assert isinstance(new_token, int)
synapse/config/_util.py
62: if isinstance(p, int):
```
which cover metrics, logic related to `jsonschema`, and replication and
data streams. AFAICS these are all internal to Synapse
* Changelog
