[AspireE2E]When executing `aspire update` out of the project folder, it will check my one driver .cs file even that does not contain apphost file

**REGRESSION INFO:** Not a regression

**INSTALL STEPS**
1. Clean machine: Windows11 25h2 x64
2. Install Aspire CLI : `irm https://aspire.dev/install.ps1 | iex`

**REPRO STEPS**
1. Open CMD, create an Aspire Express/React Starter App using following commands:

`aspire new aspire-ts-starter -n React1`

1. Run `aspire update` out of the project folder

**ACTUAL**
An error appears "❌ C# apphost requires .NET SDK version 10.0.100 or later. Detected: (not found)." but my one driver project does not contain apphost, just a csproj file.

**Note**
1. This issue does not reproduce when running `aspire update` in project folder.

**EXPECTED**
The` aspire update` should just check the local machine that contains apphost file.