Fix double counting of auth server

[bernardjkim]

The auth server is already included within the inventory of connected resources. This results in the auth server being counted twice.

This would explain why the sum of registered servers on a new Cloud cluster was 16 when it should be 14 (12 Proxy and 2 Auth)

To verify, I added some logs while iterating over the inventory.

# Logs from teleport-auth-69db99c78c-wb8gl
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-5c45589996-jbv47, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-cff858d78-4sp27, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-auth-69db99c78c-wb8gl, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-77b4b69d79-zktf7, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-5c45589996-l7pnn, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-cd9b77799-kd2ln, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-5c7bb64c97-nn85h, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-77b4b69d79-2vrhf, Version: 15.0.0-dev","timestamp":"2023-09-20T00:41:03Z"}

# Logs from teleport-auth-69db99c78c-lx949
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-746c898b7-ht8jp, Version: 15.0.0-dev","timestamp":"2023-09-20T00:40:16Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-746c898b7-6tqw2, Version: 15.0.0-dev","timestamp":"2023-09-20T00:40:16Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-auth-69db99c78c-lx949, Version: 15.0.0-dev","timestamp":"2023-09-20T00:40:16Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-5c7bb64c97-8plt2, Version: 15.0.0-dev","timestamp":"2023-09-20T00:40:16Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-cff858d78-2m7jx, Version: 15.0.0-dev","timestamp":"2023-09-20T00:40:16Z"}
{"caller":"auth/auth.go:1334","component":"auth","level":"info","message":"Hostname: teleport-proxy-cd9b77799-lrvkj, Version: 15.0.0-dev","timestamp":"2023-09-20T00:40:16Z"}

[public-teleport-github-review-bot]

@bernardjkim See the table below for backport results.

Branch	Result
branch/v13	Create PR
branch/v14	Create PR