Bump target and lib to es2020 in tsconfig.json

tsconfig.json

@@ -6,7 +6,7 @@
     "esModuleInterop": true,
     "experimentalDecorators": true,
     "forceConsistentCasingInFileNames": true,
-    "lib": ["es6"],
+    "lib": ["es2020"],
     "module": "commonjs",
     "moduleResolution": "node",
     "noImplicitAny": true,
@@ -14,7 +14,7 @@
     "resolveJsonModule": true,
     "sourceMap": true,
     "strict": true,
-    "target": "es6"
+    "target": "es2020"
   },
   "exclude": ["node_modules"],
   "files": ["./hardhat.config.ts"],