Multigres (High Availability) projects ship with legacy API keys
disabled and the management API rejects re-enabling them, so the
Dashboard should not surface them at all.
Hides the "Legacy anon, service_role API keys" tab, renders an empty
state on the legacy page for direct URL access, and drops the "Copy
anonymous API key" / "Copy service API key" commands from the command
menu. Non-HA projects are unchanged.
Fixes FE-4276
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* High Availability projects now hide legacy API key navigation and
commands.
* Legacy API key settings display an unavailable message for High
Availability projects.
* Publishable and secret key options remain available where supported.
* Other projects continue to provide access to supported legacy API key
options.
* **Bug Fixes**
* Prevented unsupported legacy API key controls from appearing on High
Availability projects.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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Co-authored-by: Joshen Lim <joshenlimek@gmail.com>
