vetkd: key_1 listed as mainnet-only but local-dev section says the local network provisions it

[raymondk]

• skills/vetkd/SKILL.md:44-45 — table: test_key_1 Environment = "Local + Mainnet"; key_1 Environment = "Mainnet".
• skills/vetkd/SKILL.md:570 — "icp network start -d # Start the local network (provisions test_key_1 and key_1 automatically)".

One of the two claims about local availability of key_1 is wrong.