Backslash in `obj` folder name with `.esproj` projects on macOS

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

Projects with the `.esproj` extension have debug information outputted to `obj\Debug` instead of `obj/Debug`, creating a new folder entirely instead of a subfolder. This is not ignored by the default `.gitignore` generated by `dotnet new gitignore`.

### Expected Behavior

The folder should be named `obj/Debug` instead of `obj\Debug`.

### Steps To Reproduce

Create a new project with `aspire new aspire-ts-cs-starter -n ` on macOS. The folder in question is located at `/frontend/obj\Debug`.

### Exceptions (if any)

_No response_

### .NET Version info

```
.NET SDK:
Version: 10.0.201
Commit: 4d3023de60
Workload version: 10.0.200-manifests.0793c108
MSBuild version: 18.3.0-release-26153-122+4d3023de6

Runtime Environment:
OS Name: Mac OS X
OS Version: 26.2
OS Platform: Darwin
RID: osx-arm64
Base Path: /usr/local/share/dotnet/sdk/10.0.201/

.NET workloads installed:
There are no installed workloads to display.
Configured to use workload sets when installing new manifests.
No workload sets are installed. Run "dotnet workload restore" to install a workload set.

Host:
Version: 10.0.5
Architecture: arm64
Commit: a612c2a105

.NET SDKs installed:
10.0.201 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 10.0.5 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 10.0.5 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
None

Environment variables:
Not set

global.json file:
Not found

Learn more:
https://aka.ms/dotnet/info

Download .NET:
https://aka.ms/dotnet/download
```

### Anything else?

`aspire --version`: `13.1.2+895a2f0b09d747a052aaaf0273d55ad0e2dc95b0`