This feature can lead to correctness issues with binary detection (see
https://gitlab.com/gitlab-org/gitlab/-/issues/340013) since blob data is
not guaranteed to be loaded entirely when detection is run.

Benchmarks in https://gitlab.com/gitlab-org/gitlab/-/issues/34001 show
on staging that the cost of Redis lookups can be 80x slower than just
running Charlock Holmes of up to 8000 characters per file.

Relates to:

* https://gitlab.com/gitlab-org/gitlab/-/issues/340013
* https://gitlab.com/gitlab-org/gitlab/-/issues/328819

Changelog: changed