fix(lambda): filterRule.null() returns empty array (aws#31701)

### Issue # (if applicable)

Closes aws#31458.

### Reason for this change

According to the documentation [here](https://docs.aws.amazon.com/lambda/latest/dg/invocation-eventfiltering.html#filtering-syntax), the FilterPattern should be [null]. However, the function FilterRule.null() currently returns an empty array [] instead. It results an invalid filter pattern definition.

### Description of changes
Change the return value from `[]` to `[null]`

### Description of how you validated changes

Add an integration test to validate the new return value. Also with the old return value, the deployment will fail with error `Invalid request provided: Invalid filter pattern definition.` so it should break existing customers.

### Checklist
- [x] 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)

**BREAKING CHANGE**: The function return value changes from `String[]` to `any` which could be a breaking change in some cases. However, the previous return value would fail the deployment hence it reduces the risk of breaking change.

----

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

allowed-breaking-changes.txt

@@ -932,4 +932,8 @@ removed:aws-cdk-lib.aws_ec2.WindowsVersion.WINDOWS_SERVER_2022_SWEDISH_FULL_BASE
 removed:aws-cdk-lib.aws_ec2.WindowsVersion.WINDOWS_SERVER_2022_TURKISH_FULL_BASE_2023_11_15
 removed:aws-cdk-lib.aws_ec2.WindowsVersion.WINDOWS_SERVER_2022_TURKISH_FULL_BASE_2023_12_13
 removed:aws-cdk-lib.aws_ec2.WindowsVersion.WINDOWS_SERVER_2022_TURKISH_FULL_BASE_2024_01_16
-removed:aws-cdk-lib.aws_ec2.WindowsVersion.WINDOWS_SERVER_2022_TURKISH_FULL_BASE_2024_02_14
+removed:aws-cdk-lib.aws_ec2.WindowsVersion.WINDOWS_SERVER_2022_TURKISH_FULL_BASE_2024_02_14
+
+# null() return a [] which is invalid filter rule. It should return [null].
+# Hence the return type changes from string[] to any
+change-return-type:aws-cdk-lib.aws_lambda.FilterRule.null

packages/@aws-cdk-testing/framework-integ/test/aws-lambda-event-sources/test/integ.sqs-null-filter.js.snapshot/lambda-event-source-filter-criteria-null.template.json

@@ -0,0 +1,148 @@
+{
+ "Resources": {
+  "FuncServiceRole49680D06": {
+   "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"
+       ]
+      ]
+     }
+    ]
+   }
+  },
+  "FuncServiceRoleDefaultPolicy588DA782": {
+   "Type": "AWS::IAM::Policy",
+   "Properties": {
+    "PolicyDocument": {
+     "Statement": [
+      {
+       "Action": [
+        "sqs:ChangeMessageVisibility",
+        "sqs:DeleteMessage",
+        "sqs:GetQueueAttributes",
+        "sqs:GetQueueUrl",
+        "sqs:ReceiveMessage"
+       ],
+       "Effect": "Allow",
+       "Resource": {
+        "Fn::GetAtt": [
+         "Queue4A7E3555",
+         "Arn"
+        ]
+       }
+      }
+     ],
+     "Version": "2012-10-17"
+    },
+    "PolicyName": "FuncServiceRoleDefaultPolicy588DA782",
+    "Roles": [
+     {
+      "Ref": "FuncServiceRole49680D06"
+     }
+    ]
+   }
+  },
+  "Func217E03A4": {
+   "Type": "AWS::Lambda::Function",
+   "Properties": {
+    "Code": {
+     "ZipFile": "exports.handler = async function handler(event) {\n    console.log('event:', JSON.stringify(event, undefined, 2));\n    return { event };\n}"
+    },
+    "Handler": "index.handler",
+    "Role": {
+     "Fn::GetAtt": [
+      "FuncServiceRole49680D06",
+      "Arn"
+     ]
+    },
+    "Runtime": "nodejs18.x"
+   },
+   "DependsOn": [
+    "FuncServiceRoleDefaultPolicy588DA782",
+    "FuncServiceRole49680D06"
+   ]
+  },
+  "FuncSqsEventSourcelambdaeventsourcefiltercriterianullQueueCEF92D9AD2F13C0B": {
+   "Type": "AWS::Lambda::EventSourceMapping",
+   "Properties": {
+    "BatchSize": 5,
+    "EventSourceArn": {
+     "Fn::GetAtt": [
+      "Queue4A7E3555",
+      "Arn"
+     ]
+    },
+    "FilterCriteria": {
+     "Filters": [
+      {
+       "Pattern": "{\"body\":{\"id\":[null]}}"
+      }
+     ]
+    },
+    "FunctionName": {
+     "Ref": "Func217E03A4"
+    }
+   }
+  },
+  "Queue4A7E3555": {
+   "Type": "AWS::SQS::Queue",
+   "UpdateReplacePolicy": "Delete",
+   "DeletionPolicy": "Delete"
+  }
+ },
+ "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."
+    }
+   ]
+  }
+ }
+}