feat: add Ultra EVM Mainnet (#3277)

Add Ultra EVM Mainnet chain

Author: Duncan-Ultra

.changeset/grumpy-moons-stare.md

@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Added Ultra EVM Mainnet chain

src/chains/definitions/ultra.ts

@@ -0,0 +1,20 @@
+import { defineChain } from '../../utils/chain/defineChain.js'
+
+export const ultra = /*#__PURE__*/ defineChain({
+  id: 19991,
+  name: 'Ultra EVM',
+  nativeCurrency: {
+    decimals: 18,
+    name: 'Ultra Token',
+    symbol: 'UOS',
+  },
+  rpcUrls: {
+    default: { http: ['https://evm.ultra.eosusa.io'] },
+  },
+  blockExplorers: {
+    default: {
+      name: 'Ultra EVM Explorer',
+      url: 'https://evmexplorer.ultra.io',
+    },
+  },
+})

src/chains/index.ts

@@ -467,6 +467,7 @@ export { treasure } from './definitions/treasure.js'
 export { treasureTopaz } from './definitions/treasureTopaz.js'
 export { tron } from './definitions/tron.js'
 export { ubiq } from './definitions/ubiq.js'
+export { ultra } from './definitions/ultra.js'
 export { ultraTestnet } from './definitions/ultraTestnet.js'
 export { ultron } from './definitions/ultron.js'
 export { ultronTestnet } from './definitions/ultronTestnet.js'