Update network versions on README (#3299)

Automated version updates:
  - Fuel Ignition: 0.48.1
  - Testnet: 0.48.1
  - Devnet: 0.48.1

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

github-actions[bot] committed 3mo ago

56950ee3493b6359577b90eae1821c76e7b69b4b

Parent: b7acef9

Committed by GitHub <noreply@github.com> on 5/13/2026, 2:36:12 PM