Formatting of call argument split on operator reduces readability

The following code is formatted the same with `black`, `black --preview`, and `ruff format`:

```python
if True:
# Limit the number of items displayed per rule to between 10 and 200
max_display_per_rule = max(
10,
200
// len(
set(all_rule_changes.added_violations.keys()).union(
all_rule_changes.removed_violations.keys()
)
),
)
```

Moving the operator onto a new line makes it look like an argument in the function call.

Perhaps the following would be clearer?

```python
if True:
# Limit the number of items displayed per rule to between 10 and 200
max_display_per_rule = max(
10,
200 // len(
set(all_rule_changes.added_violations.keys()).union(
all_rule_changes.removed_violations.keys()
)
),
)
```

Use the two Python examples in issue #8261 as the starting point and inspect Ruff's formatter behavior for operators inside split call arguments. Compare the current output with the proposed output and add or update a regression test if the formatter test suite provides one; done means the operator remains on the expression line as shown in the second example.

Written by the indexing model from the issue text.