Correct stale deprecation versions in API comments

[hl662]

Closes #9287

Why

Some deprecated API comments are still stamped as @deprecated in 5.1.9 even when the replacement API was introduced later in 5.5.0 or 5.9.0. That leaves users with the wrong migration timeline in editor warnings and generated docs, and it makes the deprecation metadata inconsistent with the actual history we already traced.

This PR manually corrects the already-triaged stale comments so the published deprecation guidance matches the release where those APIs were actually deprecated. It is intentionally separate from the pipeline fix that restores version syncing for future deprecation rewrites.

What

Asset	Why it exists
core/backend deprecation comment updates	Most stale 5.1.9 deprecations live here, so these edits realign backend API comments with the actual 5.9.0 deprecation wave and its existing removal-date buckets.
core/common and core/frontend deprecation comment updates	These comments pointed to replacement APIs introduced later than 5.1.9, so they now match the same 5.9.0 migration timeline as the backend APIs they pair with.
domains/linear-referencing/backend deprecation comment updates	The linear-referencing editing APIs were part of the same later deprecation wave, so their comments now point to the correct 5.9.0 version.
core/geometry deprecation comment updates	These two geometry deprecations were introduced in 5.5.0, so they need a separate version correction instead of being lumped into the 5.9.0 bucket.

No runtime behavior changed; this is a comment-only cleanup of stale deprecation metadata across 28 files.

Validation

• node common/scripts/install-run-rush.js install --bypass-policy
• node common/scripts/install-run-rush.js build --to @itwin/core-backend --to @itwin/core-common --to @itwin/core-frontend --to @itwin/core-geometry --to @itwin/linear-referencing-backend
• cd core/geometry && node ../../common/scripts/install-run-rushx.js docs
• cd core/common && node ../../common/scripts/install-run-rushx.js docs
• cd core/backend && node ../../common/scripts/install-run-rushx.js docs
• cd core/frontend && node ../../common/scripts/install-run-rushx.js docs
• cd domains/linear-referencing/backend && node ../../../common/scripts/install-run-rushx.js docs
• node common/scripts/install-run-rush.js extract-api --to @itwin/core-backend --to @itwin/core-common --to @itwin/core-frontend --to @itwin/core-geometry --to @itwin/linear-referencing-backend
• rg -n "@deprecated in 5\.1\.9" core presentation domains editor extensions tools ui utils full-stack-tests common → no matches in the targeted source roots after the cleanup

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[dassaf4]

core-geometry looks good, thanks.

[aruniverse]

are there any other incorrect deprecated in version comments than just the ones in here?

[dassaf4]

What's the best practice for inserting the right deprecation version? Or is this automatic going forward?

[hl662]

are there any other incorrect deprecated in version comments than just the ones in here?

We've fixed all the currently-audited stale incorrect deprecation-version comments attributable to the 5.1.9 hardcoded policy problem. If there are any other incorrect deprecated version comments, that would come from human error, manually written deprecation comments disclosing which major/minor/patch versions are not affected by this problem - in that case, that should be part of a different PR if we had any remaining, but that'll be more fine combing through the repo

[hl662]

What's the best practice for inserting the right deprecation version? Or is this automatic going forward?

I would defer to my senior colleagues to answer, I'm sure knowing what could happen I will be manually stamping which version I deprecate my apis 😃