adds Gensyn mainnet (685689) (#7942)

* Add gensyn mainnet (685686)

* Update eip155-685686.json

* Update and rename eip155-685686.json to eip155-685689.json

Author: h-grieve

_data/chains/eip155-685689.json

@@ -0,0 +1,16 @@
+{
+  "name": "Gensyn Mainnet",
+  "chain": "Gensyn",
+  "rpc": [],
+  "faucets": [],
+  "nativeCurrency": {
+    "name": "Ether",
+    "symbol": "ETH",
+    "decimals": 18
+  },
+  "infoURL": "https://www.gensyn.ai/",
+  "shortName": "gensyn-mainnet",
+  "chainId": 685689,
+  "networkId": 685689,
+  "status": "incubating"
+}