aws cloudformation package mixes two lambda functions with wrong indentation

### Describe the bug

When running `aws cloudformation package` the output template mixes two lambda functions if the second one has an indentation bug.

### Expected Behavior

abort with a validation error

### Current Behavior

All properties of the 2nd lambda overrides the properties of the 1st lambda.
The 2nd lambda becomes `null`.

### Reproduction Steps

Create a template called `indentation-bug.yml`

```
AWSTemplateFormatVersion: 2010-09-09
Transform: [AWS::Serverless-2016-10-31]

Description: AWS Lambda bug

Resources:
LambdaOne:
Type: AWS::Serverless::Function
Properties:
InlineCode: |
exports.handler = async (event) => {
return {
statusCode: 200,
body: JSON.stringify('Hello from LambdaOne!'),
};
};
MemorySize: 1024
EventInvokeConfig:
MaximumRetryAttempts: 0
Events:
SignupResource:
Type: Api
Properties:
Path: /one
Method: ANY

LambdaTwo:
Type: AWS::Serverless::Function
Properties:
InlineCode: |
exports.handler = async (event) => {
return {
statusCode: 200,
body: JSON.stringify('Hello from LambdaOne!'),
};
};
MemorySize: 1024
EventInvokeConfig:
MaximumRetryAttempts: 0
Events:
SignupResource:
Type: Api
Properties:
Path: /two
Method: ANY
```

run `aws cloudformation package`

```
aws cloudformation package --template-file ./indentation-bug.yml --s3-bucket "your-s3-bucket" --output-template indentation-bug-package.yml --profile your-profile
```

### Possible Solution

_No response_

### Additional Information/Context

The current output from package:

```
AWSTemplateFormatVersion: 2010-09-09
Transform:
- AWS::Serverless-2016-10-31
Description: AWS Lambda bug
Resources:
LambdaOne:
Type: AWS::Serverless::Function
Properties:
InlineCode: "exports.handler = async (event) => {\n return {\n statusCode:\
\ 200,\n body: JSON.stringify('Hello from LambdaOne!'),\n };\n};\n"
MemorySize: 1024
EventInvokeConfig:
MaximumRetryAttempts: 0
Events:
SignupResource:
Type: Api
Properties:
Path: /two
Method: ANY
CodeUri: s3://dev-develop-augmentt-source-code-storage/9cba226edf2a273d23d226a3927776a9
LambdaTwo: null
```

Instead of silently mixing LambdaOne with LambdaTwo and causing a bug, it would be better to just error out on invalid template syntax.

### CLI version used

2.17.14

### Environment details (OS name and version, etc.)

ubuntu-latest (GitHub Actions), Mac M1