Permanently disable port 55680 in Collector version 0.30.0

[alolita]

@mxiamxia has removed all the legacy port(55680) mentions across the OpenTelemetry repos. The port will be disabled in OTel Collector v0.30.0 per the discussion in #3256 (comment)

[alolita]

@bogdandrutu PR #3101 was closed. What needs to be done here? Let us know so that @mxiamxia can resolve this.

[mxiamxia]

From the previous discussion, we need some baking time before we'll going to remove the old gRPC port(55680). I think now is a good time to remove it. I also want to confirm if we should also remove the legacy HTTP port(55681) as well? @bogdandrutu @alolita