Extracted from #9558

if provisioner daemons are out of date with the server version, unexpected behavior can occur. the health check endpoint /api/v2/debug/health should display configured, provisioners, and their versions.

TODOs:

• feat: purge old provisioner daemons #10949 Prune inactive provisioner daemons from database.
• feat(coderd): add last_seen_at and version to provisioner_daemons table #11033 Add provisioner_daemon.version to database.
• feat(cli): allow specifying name of provisioner daemon #11077 Stabilize provisioner name generation (no more gallant_galois0).
• feat(coderd/database): add UpsertProvisionerDaemons query #11178 Add support for upserting provisioner daemons
• Populate provisionerdaemons feat(coderd): insert provisioner daemons #11207
• Add "heartbeat" to connected provisioner daemons feat(coderd): insert provisioner daemons #11207
• Add major.minor version check of active provisioner daemons. feat(coderd): add provisioner_daemons to /debug/health endpoint #11393, fix(coderd/healthcheck): add daemon-specific warnings to healthcheck output #11490
• Build the health check section for provisioner daemons. feat(site): add healthcheck page for provisioner daemons #11494