(cli): Provide a way to ignore "This app contains no stacks"

### Describe the feature

It would be nice if I could ignore the "This app contains no stacks" error message specifically.

@msambol added `--ignore-no-stacks` to the `cdk deploy` command with #28387, but this flag should be respected on all commands that fail if stacks are not present (e.g., `synth`, `diff,` `deploy`, etc.)

### Use Case

In many cases, I have a dev and prod AWS account. When I first develop a new CDK project, I often want to only deploy the dev account, while later deploying to dev and prod. I often write this code like this:

```ts
#!/usr/bin/env node
import 'source-map-support/register';
import * as cdk from 'aws-cdk-lib';
import { TestCdkStack } from '../lib/test-cdk-stack';

const app = new cdk.App();

// Assume 12345678910 is my dev account number
if (process.env.CDK_DEFAULT_ACCOUNT === "12345678910") {
new TestCdkStack(app, 'TestCdkStack', {
/* If you don't specify 'env', this stack will be environment-agnostic.
* Account/Region-dependent features and context lookups will not work,
* but a single synthesized template can be deployed anywhere. */

/* Uncomment the next line to specialize this stack for the AWS Account
* and Region that are implied by the current CLI configuration. */
// env: { account: process.env.CDK_DEFAULT_ACCOUNT, region: process.env.CDK_DEFAULT_REGION },

/* Uncomment the next line if you know exactly what Account and Region you
* want to deploy the stack to. */
// env: { account: '123456789012', region: 'us-east-1' },

/* For more information, see https://docs.aws.amazon.com/cdk/latest/guide/environments.html */
});
}
```

However, this fails with the error message "This app contains no stacks".

You might think, "why not just set up deployment to not happen until you're ready?". My common use case is a monorepo with many projects. My CI uses `lerna` to run `cdk diff` automatically in projects that changed.

### Proposed Solution

A CLI flag like `--ignore-no-stacks` would be great. This reminds me of `jest`'s `--passWithNoTests` flag that's helpful when you've installed jest but not written tests yet.

### Other Information

I've hacked my way around this by creating this script:

```bash
#! /bin/bash
# Working around this issue: https://github.com/aws/aws-cdk/issues/28371

set -e

if [ "$CI" ] && [ "$CDK_STAGE" == 'dev' ]; then
echo "This stack does not deploy to dev"
exit 0
else
cdk "$@"
fi
```

and updating the `package.json`'s `cdk` script to call this instead.

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

2.137.0

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

MacOS Sonoma

Start with the existing --ignore-no-stacks behavior in the cdk deploy command, then trace how synth, diff, and deploy handle the no-stacks error. The change is complete when the flag consistently suppresses that error across the applicable commands, with command behavior checked for the described monorepo workflow.

Written by the indexing model from the issue text.