`pyrefly coverage report` locates suppressions at the first `#` on the line

`parse_suppressions` uses `line.find('#')`, which can hit a `#` inside a string literal:

```py
x: str = "#hash"  # type: ignore
```

```json
"type_ignores": [{"kind": "type", "codes": [], "location": {"line": 1, "column": 11}}]
```

Column 11 is the `#` in `"#hash"`; the comment starts at column 19. `ignore.rs` already has a
quote-aware `find_comment_start`.