Remove usage telemetry (PostHog) from Hamilton

[skrawcz]

Changes

ASF policy does not permit phone-home telemetry in released artifacts. This removes all PostHog event tracking while keeping hamilton/telemetry.py as a backwards-compatible no-op stub so downstream code that calls telemetry.disable_telemetry() continues to work without changes.

How I tested this

• unit tests

Notes

Checklist

• PR has an informative and human-readable title (this will be pulled into the release notes)
• Changes are limited to a single goal (no scope creep)
• Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future TODOs are captured in comments
• Project documentation has been updated if adding/changing functionality.

[Dev-iL]

My main comment is - in addition to the noop stubs, mark these methods as deprecated (via decorator, or raising a warning), and remove all traces in an upcoming major release (e.g. 2.0 or 2.1 or 3.0)