.net: error CS1009: Unrecognized escape sequence

### Describe the bug

When the docstrings for elements contain a `\`, the .NET compiler doesn't like it

### Expected Behavior

Don't fail compilation

### Current Behavior

This PR introduces backslashes that cause a jsii compilation failure: https://github.com/aws/aws-cdk/pull/28737/files

### Reproduction Steps

-

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### SDK version used

-

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

-

Start by examining the linked pull request diff to identify where the docstrings containing backslashes enter the .NET output. Reproduce the jsii compilation failure, then verify that the generated .NET code compiles successfully when those docstrings include backslashes.

Written by the indexing model from the issue text.