fix: For treefmt in CI, use --no-cache

[RasmusRendal]

It was breaking some downstream users of ES, and is recommended by the
official docs.

[cursor]

PR Summary

Low Risk
CI-only environment variable for the standards pre-commit job; no runtime or application logic changes.

Overview
Sets TREEFMT_NO_CACHE=1 on the CI step that runs prek --all-files so treefmt skips its cache during pre-commit checks.

The change is defined in check-pre-commit-hooks.nix (the workflow YAML is generated). Comments note this avoids cache timeouts on some runners and aligns with treefmt’s CI guidance; --fail-on-change is not added because prek already enforces formatting failures.

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