tsh ssh with load all CAs does not work

[atburke]

Expected behavior:
When logged in to the root cluster of a trusted cluster pair where auth_service.load_all_cas is true, tsh ssh <leaf-node-addr> should work.

Current behavior:
tsh ssh <leaf-node-addr> fails with error direct dialing to nodes not found in inventory is not supported.

Bug details:

• Teleport version: v14.0.0-alpha.2
• Recreation steps: Follow tsh CA loading section of testplan

#30323 removed support for direct dialing of nodes, which was the only case where load_all_cas applied. It may make sense to also deprecate loading all CAs for tsh ssh.

Edit: Works correctly when TELEPORT_UNSTABLE_UNLISTED_AGENT_DIALING=yes in the proxy's environment.

[zmb3]

See also #31162

[galbeniluz]

Hi, we've recently upgraded our cluster to v14.0.3 and we are experiencing the same issue