cdk-assets: Ziping and uploading empty S3 folder

### Describe the bug

I recently created my own CodePipeline with a step to synth the CDK folder and upload whatever need to be uploaded using cdk-assets, here is my synth definition:

```
iaac_build_project = codebuild.Project(self, "IaaCBuildProject",
environment=codebuild.BuildEnvironment(
build_image=codebuild.LinuxBuildImage.AMAZON_LINUX_2_5
),
build_spec=codebuild.BuildSpec.from_object({
"version": "0.2",
"phases": {
"install": {
"runtime-versions": {
"nodejs": 18,
"python": "3.11"
},
"commands": [
"npm install -g aws-cdk",
"pip install -r requirements.txt"
]
},
"build": {
"commands": [
"npx cdk synth -c TargetStack=$STACK_NAME",
]
}
},
"artifacts": {
"files": "cdk.out/*"
}
}),
role=code_build_role
)
```

And this is the step that uses cdk-assets

```
cdk_deploy_assets = codebuild.Project(self, "CDKDeployAssets",
environment=codebuild.BuildEnvironment(
build_image=codebuild.LinuxBuildImage.AMAZON_LINUX_2_5
),
build_spec=codebuild.BuildSpec.from_object({
"version": "0.2",
"phases": {
"install": {
"runtime-versions": {
"nodejs": 18,
"python": "3.11"
},
"commands": [
"npm install -g cdk-assets@latest",
"tmpfile=/tmp/aws-session-file",
"aws sts assume-role --role-arn $CDK_ROLE --role-session-name `whoami`-`date +%d%m%y`-session > $tmpfile",
"export AWS_ACCESS_KEY_ID=`cat $tmpfile|jq -c '.Credentials.AccessKeyId'|tr -d '\"'`",
"export AWS_SECRET_ACCESS_KEY=`cat $tmpfile |jq -c '.Credentials.SecretAccessKey'|tr -d '\"'`",
"export AWS_SESSION_TOKEN=`cat $tmpfile|jq -c '.Credentials.SessionToken'|tr -d '\"'`",
]
},
"build": {
"commands": [
"export AWS_PROFILE=assumed-role",
"cat cdk.out/$STACK_NAME.assets.json | jq 'del(.'$KEY')' > cdk.out/assets.json",
"cat cdk.out/assets.json",
"cdk-assets publish -p cdk.out/assets.json"
]
}
}
}),
role=code_build_role
)
```

Althought logs show that assets are being publish, whenever I check S3 zip folder are empty. Any ideas? My folder only contain a single index.py file its defined using the following snippet:
```

lbd_function = lambda_.Function(self, "lbdFunction",
code=lambda_.Code.from_asset("./lambda/path_to_code"),
handler="index.handler",
timeout=Duration.seconds(30),
runtime=lambda_.Runtime.PYTHON_3_11,
memory_size=256,
role=lambda_role,
function_name="lbd_function"
)
```

### Expected Behavior

Uploaded folder are zipped with the index.py file

### Current Behavior

Uploaded folder are zipped with no contents

### Reproduction Steps

Create a CodePipeline and use the definitions provided up top.

### Possible Solution

_No response_

### Additional Information/Context

It's seems this doesn't happen on my local, any ideas?

### CDK CLI Version

2.110.0

### Framework Version

_No response_

### Node.js Version

18

### OS

Amazon Linux 2023

### Language

Python

### Language Version

Python 3.11

### Other information

_No response_

Start with the generated cdk.out/$STACK_NAME.assets.json and the derived cdk.out/assets.json, then inspect the cdk-assets publish step in the provided CodeBuild definition. Compare the local and Amazon Linux 2023 outputs for the lambda/path_to_code asset. Done means cdk-assets publishes a zip containing index.py rather than an empty folder.

Written by the indexing model from the issue text.