[Issue] azd template list in DevCenter mode fails silently when not logged in

[MaxHorstmann]

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Output from azd version
azd version 1.10.3 (commit 0595f33)

Describe the bug
In DevCenter mode, azd template list (and likely other commands) fails silently when not logged in.

To Reproduce

$ azd config set platform.type devcenter
$ azd template list         
Name      Source    Repository Path

... huh? where are my templates?

$ azd template list --debug
2024/10/24 09:22:52 main.go:56: azd version: 1.10.3 (commit 0595f33fe948ee6df3da492567e3e7943cb9a733)
2024/10/24 09:22:52 main.go:214: using cached latest version: 1.10.3 (expires on: 2024-10-24T15:00:59Z)
2024/10/24 09:22:52 middleware.go:108: running middleware 'debug'
2024/10/24 09:22:52 middleware.go:108: running middleware 'ux'
2024/10/24 09:22:52 middleware.go:108: running middleware 'telemetry'
2024/10/24 09:22:52 telemetry.go:43: TraceID: b996e83f87a5047e2e662147be20819d
  |       | Retrieving templates...2024/10/24 09:22:52 template_manager.go:173: failed to create source: unable to create template source 'devcenter': invalid template source type, 'devcenter', not logged in, run `azd auth login` to login
Name      Source    Repository Path

Oh - I'm not logged in.

$ azd auth login
Logged in to Azure.
$ azd template list
<works>

Expected behavior
azd template list should already display "not logged in, run azd auth login to login"

Environment
MacOS 15.0.1 (24A348)