fix(lambda-nodejs): remove smithy models from bundling for AWS SDK v3…

… runtimes (under feature flag) (#31639)

### Issue # (if applicable)

Closes #31610

### Reason for this change

for Node 18+ runtimes, since AWS Lambda includes AWS SDK v3 by default, and CDK excludes all the `@aws-sdk/*` packages because they’re expected to already be present. However, the CDK currently removes only the `@aws-sdk/*` packages when bundling for Node 18+ runtimes, but it does not remove the `@smithy/*` packages. This can cause a mismatch in versions between the `@smithy/*` packages and the AWS SDK packages that AWS Lambda provides.

The mismatch can happen in the following scenarios. This is a pretty edge case but customers did encounter this issue.
```
/user-app/node_modules/
  - /@smithy/* (v123) <-- this gets used because it wasn't deleted
  - /@aws-sdk/*  (v123) <-- CDK removes `@aws-sdk/*` currently
/lambda-hidden-folder/node_modules
  - /@smithy/* (v456)
  - /@aws-sdk/* (v456) <-- this gets used as fallback since the module is removed from node_modules by CDK
```

### Description of changes

Add a feature flag. When feature flag is set to true, we will also remove smithy models.

### Description of how you validated changes

Added unit tests and integration tests.

### Checklist
- [ ] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk-testing/framework-integ/test/aws-lambda-nodejs/test/integ.function-exclude-smithy-models.js.snapshot/cdk-integ-lambda-nodejs-18-exclude-smithy.template.json

@@ -0,0 +1,91 @@
+{
+ "Resources": {
+  "NodeJsFunctionServiceRole9AE046B6": {
+   "Type": "AWS::IAM::Role",
+   "Properties": {
+    "AssumeRolePolicyDocument": {
+     "Statement": [
+      {
+       "Action": "sts:AssumeRole",
+       "Effect": "Allow",
+       "Principal": {
+        "Service": "lambda.amazonaws.com"
+       }
+      }
+     ],
+     "Version": "2012-10-17"
+    },
+    "ManagedPolicyArns": [
+     {
+      "Fn::Join": [
+       "",
+       [
+        "arn:",
+        {
+         "Ref": "AWS::Partition"
+        },
+        ":iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
+       ]
+      ]
+     }
+    ]
+   }
+  },
+  "NodeJsFunction6DD2A8DD": {
+   "Type": "AWS::Lambda::Function",
+   "Properties": {
+    "Code": {
+     "S3Bucket": {
+      "Fn::Sub": "cdk-hnb659fds-assets-${AWS::AccountId}-${AWS::Region}"
+     },
+     "S3Key": "5f1efdee2910b237bc92c947c2621e653fadf9ce9ef02e797da9ec166a2d4270.zip"
+    },
+    "Handler": "index.handler",
+    "Role": {
+     "Fn::GetAtt": [
+      "NodeJsFunctionServiceRole9AE046B6",
+      "Arn"
+     ]
+    },
+    "Runtime": "nodejs18.x"
+   },
+   "DependsOn": [
+    "NodeJsFunctionServiceRole9AE046B6"
+   ]
+  }
+ },
+ "Parameters": {
+  "BootstrapVersion": {
+   "Type": "AWS::SSM::Parameter::Value<String>",
+   "Default": "/cdk-bootstrap/hnb659fds/version",
+   "Description": "Version of the CDK Bootstrap resources in this environment, automatically retrieved from SSM Parameter Store. [cdk:skip]"
+  }
+ },
+ "Rules": {
+  "CheckBootstrapVersion": {
+   "Assertions": [
+    {
+     "Assert": {
+      "Fn::Not": [
+       {
+        "Fn::Contains": [
+         [
+          "1",
+          "2",
+          "3",
+          "4",
+          "5"
+         ],
+         {
+          "Ref": "BootstrapVersion"
+         }
+        ]
+       }
+      ]
+     },
+     "AssertDescription": "CDK bootstrap stack version 6 required. Please run 'cdk bootstrap' with a recent version of the CDK CLI."
+    }
+   ]
+  }
+ }
+}