chore: move printWranglerBanner for secret delete into handler

[KianNH]

What this PR solves / how to test

Moves the banner into the args handler like the rest of the commands as this command was printing the banner in the --help output.

➜  ~ npx wrangler secret delete --help

 ⛅️ wrangler 3.78.3 (update available 3.81.0)
-------------------------------------------------------

wrangler secret delete <key>

Delete a secret variable from a Worker

POSITIONALS
  key  The variable name to be accessible in the Worker  [string] [required]

GLOBAL FLAGS
  -j, --experimental-json-config  Experimental: support wrangler.json  [boolean]
  -c, --config                    Path to .toml configuration file  [string]
  -e, --env                       Environment to use for operations and .env files  [string]
  -h, --help                      Show help  [boolean]
  -v, --version                   Show version number  [boolean]

OPTIONS
      --name  Name of the Worker  [string]

➜  ~ npx wrangler secret put --help
wrangler secret put <key>

Create or update a secret variable for a Worker

POSITIONALS
  key  The variable name to be accessible in the Worker  [string] [required]

GLOBAL FLAGS
  -j, --experimental-json-config  Experimental: support wrangler.json  [boolean]
  -c, --config                    Path to .toml configuration file  [string]
  -e, --env                       Environment to use for operations and .env files  [string]
  -h, --help                      Show help  [boolean]
  -v, --version                   Show version number  [boolean]

OPTIONS
      --name  Name of the Worker  [string]