Update network versions on README (#3151)

Automated version updates:
  - Fuel Ignition: 0.47.1
  - Testnet: 0.47.1
  - Devnet: 0.47.1

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Updates README network table to set Fuel Ignition version to 0.47.1.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
59250841590e27d22c0e083b804a440c1088d940. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Green Baneling <XgreenX9999@gmail.com>