PHG004: Potential regression

Recently on updating Ruff, I started getting ``PGH004`` errors for a paragraph comment describing ``#noqa`` handling [^1]. I've attached a minimal reproducer below; the errors started appearing in Ruff 0.0.281 and a warning which previously appeared is now absent in Ruff 0.0.284.

My suggested remedy would be to only match a ``noqa`` comment if there are only whitespace tokens between the comment marker and the ``noqa`` token.

A

```python
# A sentence talking about using #noqa in prose.
# A new sentence talking about using #noqa.
# A third sentence talking about using #noqa
```

```console
$ pip install "ruff==0.0.280" --quiet
$ ruff check pgh004.py --isolated --select PGH004
$ pip install "ruff==0.0.281" --quiet
$ ruff check pgh004.py --isolated --select PGH004
warning: Invalid `# noqa` directive on pgh004.py:2: expected `:` followed by a comma-separated list of codes (e.g., `# noqa: F401, F841`).
pgh004.py:1:34: PGH004 Use specific rule codes when using `noqa`
pgh004.py:3:40: PGH004 Use specific rule codes when using `noqa`
Found 2 errors.
$ pip install "ruff==0.0.284" --quiet
$ ruff check pgh004.py --isolated --select PGH004
pgh004.py:1:34: PGH004 Use specific rule codes when using `noqa`
pgh004.py:3:40: PGH004 Use specific rule codes when using `noqa`
Found 2 errors.
```

[^1]: The specific pararaph is:

# There is no point in having #noqa on literal blocks because
# they cannot contain references. Recognizing it would just
# completely prevent escaping the #noqa. Outside of literal
# blocks, one can always write \#noqa.

Start by reproducing the report with the pgh004.py example and the Ruff 0.0.280, 0.0.281, and 0.0.284 commands. Trace the PGH004 noqa matching behavior, then verify that prose mentioning #noqa is not matched unless only whitespace separates the comment marker and token, while actual noqa handling still works.

Written by the indexing model from the issue text.