[MeshCore P0] meshflow-bot Docker — remove legacy tag push after volunteer migration

[pskillen]

Parent epic

Part of pskillen/meshflow-api#264 ([Epic] MeshCore Phase 0) — scheduled maintenance, open after migration window.

Goal

Remove legacy Docker tag publishing from meshflow-bot CI once volunteer deployments have moved to the new image name (see #84).

When to do

• After N releases or a target date, or when usage of the legacy tag is zero / agreed by operators.

Scope

• Drop secondary/legacy tag from build workflow.
• Update docs to remove legacy references.
• Announce in Mesh Scottish / feeder channels before removal.

Depends on

• [MeshCore P0] meshflow-bot Docker build — publish new tag + keep legacy tag (migration window) #84 (dual-tag publishing)

Related

• [MeshCore P0] Repo rename tidy — meshflow-bot + meshflow-ui (docs, CI, metadata) meshflow-api#270 rename tidy umbrella