Bug: Lambda Functions in nested templates are not signed

### Description:
Configuring Lambda code signing by following [this tutorial](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/authoring-codesigning.html) works fine unless you add a nested template. SAM CLI will sign all the functions in the main template but skip Lambda functions in all nested templates.

### Steps to reproduce:
1. Create a SAM template with a signing profile, signing configuration, and one Lambda function (with code signing turned on).
2. Create a nested stack that accepts the signing profile as a parameter and has another Lambda function (with code signing turned on).
3. Run the `sam deploy --guided` command to create the `samconfig.toml` file with the signing profiles configuration for both functions.
4. Run the `sam deploy` command.

A sample SAM template can look like the following:
```yaml
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Sample main SAM template

Resources:
FunctionSignerProfile:
Type: AWS::Signer::SigningProfile
Properties:
PlatformId: AWSLambda-SHA384-ECDSA

CodeSigningConfig:
Type: AWS::Lambda::CodeSigningConfig
Properties:
Description: Turn on code signing
AllowedPublishers:
SigningProfileVersionArns:
- !GetAtt FunctionSignerProfile.ProfileVersionArn
CodeSigningPolicies:
UntrustedArtifactOnDeployment: Enforce

Function1:
Type: AWS::Serverless::Function
Properties:
CodeUri: ./path/to/func1
Handler: lambda.handler
CodeSigningConfigArn: !Ref CodeSigningConfig
Runtime: nodejs16.x
Timeout: 30

NestedStack:
Type: AWS::Serverless::Application
Properties:
Location: ./nested-template.yaml
Parameters:
SigningProfileArn: !Ref CodeSigningConfig
```

Nested template can look like the following:
```yaml
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Sample main SAM template

Parameters:
Parameters:
SigningProfileArn:
Type: String
Description: Lambda code signing profile Arn

Resources:
Function2:
Type: AWS::Serverless::Function
Properties:
CodeUri: ./path/to/func2
Handler: lambda.handler
CodeSigningConfigArn: !Ref SigningProfileArn
Runtime: nodejs16.x
Timeout: 30
```

### Observed result:
The Function1 Lambda is signed as expected, but the Fuction2 Lambda is not signed.

Here's the key part of the `sam deploy --debug` command (the full output is too long):
```bash
2023-01-20 13:15:41,726 | Sam customer defined id is more priority than other IDs. Customer defined id for resource Function1 is Function1
2023-01-20 13:15:41,768 | File with same data already exists at bucket/92c6bbf94a549c715fdf9880xxxxxxxx.zip, skipping upload
2023-01-20 13:15:41,816 | S3 Object (s3://aws-sam-cli-managed-default-samclisourcebucket-1vq9k2wio9z60/bucket/92c6bbf94a549c715fdf9880xxxxxxxx.zip) tagging information {'ResponseMetadata': {'RequestId': 'YSQWQPWXRNMNxxxx', 'HostId': '4unfDZdlLxxxx/omeGHAEAGyZUPRlgU5Ymru1S9zGQOMVowQJ9CkmEb6S+ag3vyw8cotJ6bHHjfxxxx+xxxxxx==', 'HTTPStatusCode': 200, 'HTTPHeaders': {'x-amz-id-2': '4unfDZdlLxxxx/omeGHAEAGyZUPRlgU5Ymru1S9zGQOMVowQJ9CkmEb6S+ag3vyw8cotJ6bHHjfxxxx+xxxxxx==', 'x-amz-request-id': 'YSQWQPWXRNMNVX7H', 'date': 'Fri, 20 Jan 2023 12:15:42 GMT', 'x-amz-version-id': 'xymwwpMypX4dEJc2m8hz9oo9oKxxxxxx', 'transfer-encoding': 'chunked', 'server': 'AmazonS3'}, 'RetryAttempts': 0}, 'VersionId': 'xymwwpMypX4dEJc2m8hz9oo9oKxxxxxx', 'TagSet': []}
2023-01-20 13:15:41,816 | Initiating signing job with bucket:aws-sam-cli-managed-default-samclisourcebucket-1vq9k2wio9z60 key:bucket/92c6bbf94a549c715fdf9880xxxxxxxx.zip version:xymwwpMypX4dEJc2m8hz9oo9oKxxxxxx prefix:bucket/signed_ profile name:FunctionSignerProfile_8tYP6yxxxxxx profile owner:
2023-01-20 13:15:42,309 | Initiated code signing job f46a97a1-fa66-4b99-82a3-f49dddxxxxxx
2023-01-20 13:15:47,539 | Package has successfully signed into the location aws-sam-cli-managed-default-samclisourcebucket-1vq9k2wio9z60/bucket/signed_f46a97a1-fa66-4b99-82a3-f49dddxxxxxx.zip
2023-01-20 13:15:47,540 | Sam customer defined id is more priority than other IDs. Customer defined id for resource NestedStack is NestedStack
2023-01-20 13:15:47,569 | There is no customer defined id or cdk path defined for resource CreateAuthChallenge, so we will use the resource logical id as the resource id
2023-01-20 13:15:47,627 | File with same data already exists at bucket/92c6bbf94a549c715fdf9880xxxxxxxx, skipping upload
2023-01-20 13:15:47,627 | Sam customer defined id is more priority than other IDs. Customer defined id for resource CreateAuthChallenge is CreateAuthChallenge
Uploading to bucket/cdc1d17f8d481c27be4c8e4e33xxxxxx 426453 / 426453 (100.00%)
```

### Expected result:
Both Lambda functions should be signed.

### Additional environment details (Ex: Windows, Mac, Amazon Linux etc)

1. OS: `macOs 13.1 (22C65)`
5. `sam --version`: `SAM CLI, version 1.67.0`
6. AWS region: `eu-central-1`

```
{
"version": "1.67.0"
}
```