chore: fix typo in lambda nodejs16.x runtime (#20264)

Fixed a typo in this earlier PR: #20261 , and re-ran the integration tests. 

----

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### New Features

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packages/@aws-cdk/aws-lambda/lib/runtime.ts

@@ -83,7 +83,7 @@ export class Runtime {
   /**
    * The NodeJS 16.x runtime (nodejs16.x)
    */
-  public static readonly NODEJS_16_X = new Runtime('nodejs14.x', RuntimeFamily.NODEJS, { supportsInlineCode: true });
+  public static readonly NODEJS_16_X = new Runtime('nodejs16.x', RuntimeFamily.NODEJS, { supportsInlineCode: true });
 
   /**
    * The Python 2.7 runtime (python2.7)

packages/@aws-cdk/aws-lambda/test/runtime.inlinecode.integ.snapshot/aws-cdk-lambda-runtime-inlinecode.template.json

@@ -344,7 +344,7 @@
      ]
     },
     "Handler": "index.handler",
-    "Runtime": "nodejs14.x"
+    "Runtime": "nodejs16.x"
    },
    "DependsOn": [
     "NODEJS16XServiceRoleB9DAFDFD"

packages/@aws-cdk/aws-lambda/test/runtime.inlinecode.integ.snapshot/cdk.out

@@ -1 +1 @@
-{"version":"17.0.0"}
+{"version":"18.0.0"}

packages/@aws-cdk/aws-lambda/test/runtime.inlinecode.integ.snapshot/integ.json

@@ -1,7 +1,7 @@
 {
   "version": "18.0.0",
   "testCases": {
-    "aws-lambda/test/integ.runtime.inlinecode": {
+    "integ.runtime.inlinecode": {
       "stacks": [
         "aws-cdk-lambda-runtime-inlinecode"
       ],

packages/@aws-cdk/aws-lambda/test/runtime.inlinecode.integ.snapshot/tree.json

@@ -631,7 +631,7 @@
                       ]
                     },
                     "handler": "index.handler",
-                    "runtime": "nodejs14.x"
+                    "runtime": "nodejs16.x"
                   }
                 },
                 "constructInfo": {