Diagnostics: Removes Unnecessary APIs From Public Contract

[kundadebdatta]

Pull Request Template

Description

This PR removes unnecessary APIs from diagnostics public contract

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• [] New feature (non-breaking change which adds functionality)
• [] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [] This change requires a documentation update

Closing issues

To automatically close an issue: closes #IssueNumber

Changelog

• I have added a changelog entry under ### Unreleased in changelog.md
  for the user-facing impact of this change.
• [x ] No changelog entry is required because this PR is one of:
  documentation-only, test-only, CI / build-only, or a pure internal refactor
  with no observable customer impact.

If the second box is checked, briefly justify here:

This is just an extension of the Hedged API contracts to remove some of the uncommon APIs.

[github-actions]

📝 Changelog reminder (non-blocking)

This PR touches shipped source but does not appear to update the
corresponding changelog.md.

Touched (and missing entry for):

• Microsoft.Azure.Cosmos/src/** ⇒ expected an entry in changelog.md (### Unreleased)

How to decide

Use the rubric in .github/copilot-instructions.md ("Changelog
classifier") or in CONTRIBUTING.md ("Changelog entry"). Quick
version:

• Customer-observable change (behavior, perf, memory, API) ⇒ add an entry, even if the PR is [Internal].
• Test-only / CI-only / doc-only / pure-internal-refactor with zero customer-observable effect ⇒ no entry, add the no-changelog-needed label to silence this check.
• Unsure? Default to adding a one-line entry under #### Other Changes. Reviewer will adjust.

This check is non-blocking — merge is not gated on it. The
reviewer is responsible for the final classification.

[kushagraThapar]

LGTM, thanks @kundadebdatta