[gen-wrapper-react] `lit labs gen --framework react` fails with exception

### Which package(s) are affected?

Other/unknown (please mention in description)

### Description

This is probably related to the TypeScript version changes we did recently. We need integration tests.

### Reproduction

```
➜ demo-1 lit init
Created sharable element in my-element/.
➜ demo-1 lit labs gen --package my-element --framework react --out my-element-react
No tsconfig.json found; assuming package is JavaScript.
ts.formatDiagnosticsWithColorAndContext is not a function
```

### Workaround

None

### Is this a regression?

Yes. This used to work, but now it doesn't.

### Affected versions

Lit CLI 0.6.0

### Browser/OS/Node environment

OS: macOS 13.5
Node: v19.2.0

Start by reproducing the failure with `lit labs gen --package my-element --framework react --out my-element-react` on the reported environment, then inspect the generator entry point and its TypeScript integration. Add integration coverage for React generation and consider the work done when the command completes without the `formatDiagnosticsWithColorAndContext` exception.

Written by the indexing model from the issue text.