fix(localgov-ims): add @types/node devDependency

Round 3 for deploy-blueprints. After PR #189 set tsconfig types to
["node"], tsc now fails with "Cannot find type definition file for
'node'" because the package wasn't listed as a devDependency.

ts6 dropped implicit @types/* resolution, so we need this explicitly.

Local `npm install && tsc --noEmit` exits 0 with @types/node@22.x
installed.

Author: chrisns

cloudformation/scenarios/localgov-ims/cdk/package.json

@@ -12,6 +12,7 @@
     "source-map-support": "^0.5.21"
   },
   "devDependencies": {
+    "@types/node": "^22.0.0",
     "aws-cdk": "^2.1110.0",
     "typescript": "~5.9.3"
   }