Require cyclebane>=26.9.0

[SimonHeybrock]

Summary

• Bump the minimum cyclebane version to 26.9.0, which fixes a reference-cycle bug (Avoid reference cycles in graphs cyclebane#33) where networkx report views cached on graphs (e.g. G.edges, G.out_degree) kept the graph alive until the cyclic garbage collector ran.
• In long-running pipelines that repeatedly update data, this caused unbounded memory growth and OOM kills (see detector_data leaks ~60 MB per cycle in uncollected reference cycles from sciline graph updates, OOM-killing the service esslivedata#1264, Upstream cyclebane: Graph.__setitem__ leaves ~5 self-referential graphs per call, creating collector-only garbage esslivedata#1266).

Test plan

• None needed beyond CI; ran the full test suite locally against cyclebane 26.9.0, all pass.

[SimonHeybrock]

Closing — bumping the cyclebane minimum requires dropping Python 3.11 support, which in turn surfaces pre-existing typing incompatibilities (#233) that block CI. Opening a tracking issue with details instead of working around them here.