[`flake8-simplify`] Fix `SIM911` autofix creating a syntax error (#18793)
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## Summary
The fix would create a syntax error if there wasn't a space between the
`in` keyword and the following expression.
For example:
```python
for country, stars in(zip)(flag_stars.keys(), flag_stars.values()):...
```
I also noticed that the tests for `SIM911` were note being run, so I
fixed that.
Fixes #18776
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
Add regression test
<!-- How was it tested? -->
ruff
9e9c4fe1 - [`flake8-simplify`] Fix `SIM911` autofix creating a syntax error (#18793)
