chore(triagebot): enable range-diff and review-changes-since

[weihanglo]

What does this PR try to resolve?

Enable two new triagebot features, which are already adopted in rust-lang/rust.

range-diff:

Enable comments linking to triagebot range-diff when a PR is rebased
onto a different base commit
Documentation at: https://forge.rust-lang.org/triagebot/range-diff.html

review-changes-since:

Adds at the end of a review body a link
to view the changes that happened since the review
Documentation at: https://forge.rust-lang.org/triagebot/review-changes-since.html

Summary Notes

• range-diff example comments by weihanglo
• review-changes-since example comments by weihanglo

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[weihanglo]

@rustbot note "range-diff example comments"

• Rebased without changes: feat(rustdoc): stabilize --emit flag rust#146220 (comment)
• Rebased with some changes: StateTransform: Only load pin field once. rust#147493 (comment)
• Rebased with lots of change: resolve: Preserve ambiguous glob reexports in crate metadata rust#147984 (comment)

[weihanglo]

@rustbot note "review-changes-since example comments"

• No change: a collection of simple const changes rust#146600 (review)
• Some changes: 1.91.0 release notes rust#148013 (review)