build(deps): bump python-levenshtein in /lib/spack/docs

Bumps [python-levenshtein](https://github.com/rapidfuzz/python-Levenshtein) from 0.25.1 to 0.26.1.
- [Release notes](https://github.com/rapidfuzz/python-Levenshtein/releases)
- [Changelog](https://github.com/rapidfuzz/python-Levenshtein/blob/main/HISTORY.md)
- [Commits](rapidfuzz/python-Levenshtein@v0.25.1...v0.26.1)

---
updated-dependencies:
- dependency-name: python-levenshtein
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

lib/spack/docs/requirements.txt

@@ -2,7 +2,7 @@ sphinx==8.1.3
 sphinxcontrib-programoutput==0.17
 sphinx_design==0.6.1
 sphinx-rtd-theme==3.0.1
-python-levenshtein==0.26.0
+python-levenshtein==0.26.1
 docutils==0.20.1
 pygments==2.18.0
 urllib3==2.2.3