Update v2 readme

[lrapoport-cf]

What this PR solves / how to test

Fixes N/A.

This PR updates the support messaging on the wrangler v2 readme to reflect what was recently added on the main readme with #6639.

Author has addressed the following

• Tests
  • TODO (before merge)
  • Included
  • Not necessary because: just a readme change
• E2E Tests CI Job required? (Use "e2e" label or ask maintainer to run separately)
  • I don't know
  • Required / Maybe required
  • Not required because: just a readme change
• Changeset (Changeset guidelines)
  • TODO (before merge)
  • Included
  • Not necessary because: just a readme change
• Public documentation
  • TODO (before merge)
  • Cloudflare docs PR(s):
  • Not necessary because: just a readme change

[changeset-bot]

⚠️ No Changeset found

Latest commit: eeb91f6

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