Remove trigger.enabled from version hash

[josephjclark]

Description

This aligns with the CLI and latest portability spec, see the work in OpenFn/kit#1564

This reduces diff noise when merging project through git

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[github-actions]

Security Review ✅

• S0 (project scoping): N/A — the diff only removes :enabled from trigger_keys in canonical_form/1 (lib/lightning/workflow_versions.ex:275-282); no queries or endpoints change.
• S1 (authorization): N/A — no new controller actions, LiveView events, or policy clauses are introduced.
• S2 (audit trail): N/A — no new Repo.insert/update/delete on config resources; the change affects only how a workflow-version hash is computed.