[air] Show accelerator types in compute help based on workspace

[caroline-db]

Changes

• Query AICM compute options when rendering databricks experimental air run -h config.compute, honoring -p/--profile and workspace-routing headers.
• Display only accelerators available in the workspace and supported by the local AIR CLI.
• Fall back to a labelled built-in list when workspace availability cannot be determined or the backend returns no options.

Why

Accelerator availability varies by workspace. AICM remains the source of workspace availability while the local registry remains the source of CLI capabilities and topology metadata, matching the Python AIR CLI behavior.

Tests

• Focused experimental AIR unit tests.
• All experimental AIR acceptance tests.
• Full Go unit suites and repository checks.
• Go lint, Ruff 0.15.17 checks, and git diff --check.

This PR was written by Codex.

[github-actions]

Approval status: pending

/acceptance/experimental/air/ - needs approval

4 files changed
Suggested: @ben-hansen-db
Also eligible: @vinchenzo-db, @maggiewang-db, @apeforest, @bfontain, @panchalhp-db, @pardis-beikzadeh-db

/experimental/air/ - needs approval

4 files changed
Suggested: @ben-hansen-db
Also eligible: @vinchenzo-db, @maggiewang-db, @apeforest, @bfontain, @panchalhp-db, @pardis-beikzadeh-db

_{Any maintainer (@andrewnester, @anton-107, @denik, @pietern, @shreyas-goenka, @simonfaltum, @renaudhartert-db, @janniklasrose, @lennartkats-db, @rugpanov, @rclarey) can approve all areas.
See OWNERS for ownership rules.}

[eng-dev-ecosystem-bot]

Integration test report

Commit: 7be2f78

Run: 35155404367

	Env	🔄​flaky	✅​pass	🙈​skip	Time
✅​	aws linux		276	16	4:21
✅​	aws windows		278	14	3:40
✅​	azure linux		275	16	4:11
🔄​	azure windows	1	276	14	6:06
✅​	gcp linux		276	16	4:27
✅​	gcp windows		278	14	6:21

	Test Name	azure windows
🔄​	TestAccept	🔄​f

Top 3 slowest tests (at least 2 minutes):

duration	env	testname
6:19	gcp windows	TestAccept
3:38	aws windows	TestAccept
2:48	azure windows	TestAccept