chore(ci): remove non-ascii character from pytest mark (#6303)

CI: Replacing a non-ascii character so the skip reason can be read as
string:

https://app.circleci.com/pipelines/github/DataDog/dd-trace-py/39709/workflows/bf2b7758-9363-496d-aab1-2e3ddaf21797/jobs/2666245

## Checklist
- [x] Change(s) are motivated and described in the PR description.
- [x] Testing strategy is described if automated tests are not included
in the PR.
- [x] Risk is outlined (performance impact, potential for breakage,
maintainability, etc).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] [Library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
are followed. If no release note is required, add label
`changelog/no-changelog`.
- [x] Documentation is included (in-code, generated user docs, [public
corp docs](https://github.com/DataDog/documentation/)).
- [x] Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist

- [x] Title is accurate.
- [x] No unnecessary changes are introduced.
- [x] Description motivates each change.
- [x] Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes unless absolutely necessary.
- [x] Testing strategy adequately addresses listed risk(s).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] Release note makes sense to a user of the library.
- [x] Reviewer has explicitly acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment.
- [x] Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

tests/profiling/test_main.py

@@ -58,7 +58,7 @@ def test_call_script_pprof_output(tmp_path, monkeypatch):
     return filename, pid
 
 
-@pytest.mark.skipif(six.PY2, reason="This test deadlocks randomly on Python 2")
+@pytest.mark.skipif(six.PY2, reason="This test deadlocks randomly on Python 2")
 @pytest.mark.skipif(sys.platform == "win32", reason="fork only available on Unix")
 def test_fork(tmp_path, monkeypatch):
     filename = str(tmp_path / "pprof")