Respect parenthesized generators in `has_own_parentheses` (#8100)
## Summary
When analyzing:
```python
if "root" not in (
long_tree_name_tree.split("/")[0]
for long_tree_name_tree in really_really_long_variable_name
):
msg = "Could not find root. Please try a different forest."
raise ValueError(msg)
```
We missed that the generator expression is parenthesized, because the
parentheses are _part_ of the generator -- so
`is_expression_parenthesized` returns `False`. We needed to take into
account that generators and tuples may or may not be parenthesized when
determining whether we can omit parentheses while splitting an
expression.
Closes https://github.com/astral-sh/ruff/issues/8090.
## Test Plan
No changes in similarity.
Before:
| project | similarity index | total files | changed files |
|----------------|------------------:|------------------:|------------------:|
| cpython | 0.75803 | 1799 | 1647 |
| django | 0.99983 | 2772 | 34 |
| home-assistant | 0.99953 | 10596 | 186 |
| poetry | 0.99891 | 317 | 17 |
| transformers | 0.99966 | 2657 | 330 |
| twine | 1.00000 | 33 | 0 |
| typeshed | 0.99978 | 3669 | 20 |
| warehouse | 0.99977 | 654 | 13 |
| zulip | 0.99970 | 1459 | 22 |
After:
| project | similarity index | total files | changed files |
|----------------|------------------:|------------------:|------------------:|
| cpython | 0.75803 | 1799 | 1647 |
| django | 0.99983 | 2772 | 34 |
| home-assistant | 0.99953 | 10596 | 186 |
| poetry | 0.99891 | 317 | 17 |
| transformers | 0.99966 | 2657 | 330 |
| twine | 1.00000 | 33 | 0 |
| typeshed | 0.99978 | 3669 | 20 |
| warehouse | 0.99977 | 654 | 13 |
| zulip | 0.99970 | 1459 | 22 |
