fix: added `testnet: true` to fantomTestnet.ts #763

Job	Run time
Size	5m 2s
Verify / Test (http, 1, 3)	1m 18s
Verify / Lint	30s
Verify / Test (http, 2, 3)	1m 22s
Verify / Test (http, 3, 3)	1m 22s
Verify / Test (webSocket, 1, 3)	1s
Verify / Test (webSocket, 2, 3)	1s
Verify / Test Environments (bun)	1m 13s
Verify / Test (webSocket, 3, 3)	1s
Verify / Test Environments (node-18)	1m 19s
Verify / Test Environments (node-20)	1m 9s
Verify / Vectors	1m 10s
Verify / Test Environments (node-latest)	1m 7s
Verify / Test Environments (next)	2m 39s
Verify / Test Environments (sveltekit)	2m 26s
Verify / Test Environments (tsc)	1m 27s
Verify / Test Environments (vite)	1m 55s
Verify / Build	0s
Verify / Types	0s
Verify / Wagmi	0s
	24m 2s

Provide feedback