Revert "Bump jest and @types/jest (#37)" (#40)

This reverts commit c7b19e3.

Author: RossBugginsNHS

lambdas/example-lambda/package.json

@@ -6,8 +6,8 @@
   "devDependencies": {
     "@tsconfig/node22": "^22.0.2",
     "@types/aws-lambda": "^8.10.155",
-    "@types/jest": "^30.0.0",
-    "jest": "^30.2.0",
+    "@types/jest": "^29.5.14",
+    "jest": "^29.7.0",
     "jest-mock-extended": "^3.0.7",
     "typescript": "^5.9.3"
   },