Bump igraph from 0.11.5 to 0.11.6 (#4335)

Bumps [igraph](https://github.com/igraph/python-igraph) from 0.11.5 to 0.11.6.
- [Release notes](https://github.com/igraph/python-igraph/releases)
- [Changelog](https://github.com/igraph/python-igraph/blob/main/CHANGELOG.md)
- [Commits](igraph/python-igraph@0.11.5...0.11.6)

---
updated-dependencies:
- dependency-name: igraph
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

test-requirements.txt

@@ -1,6 +1,6 @@
 coverage==7.6.0
 hypothesis==6.105.1
-igraph==0.11.5
+igraph==0.11.6
 jsonschema==4.23.0
 pre-commit==3.7.1
 pytest==8.2.2