[bug]: 5.15 Installs Cuda 128 instead of 126 on RTX2060 Super

### Is there an existing issue for this problem?

- [x] I have searched the existing issues

### Operating system

Windows

### GPU vendor

Nvidia (CUDA)

### GPU model

RTX2060 Super

### GPU VRAM

8GB

### Version number

5.15

### Browser

Microsoft Edge

### Python dependencies

_No response_

### What happened

I have two systems, one with an RTX5070 series and one with an RTX2060

When installing 5.15 on the system with a new 50 series graphics card, it installs CUDA 128, which is great; everything works as expected.

When installing on a system with RTX2060, it installs Cuda 128, which isn't supported, and it errors saying xformers isn't installed. Then nothing works. It instantly says low VRAM.

I had selected "Nvidia RTX 20XX series and below" during the installation process. It's almost like the installer ignores this and installs CUDA 128 anyway. I tried skipping this version and installing v6 RC3, but I got the same error during install.

Rolling back the installer to the previously installed version 5.12 fixes the problem, and during install, it installs CUDA 126 and everything works as expected.

### What you expected to happen

Install InvokeAI selecting "Nvidia RTX 20XX series and below" during the installation process, and the installer to install the correct CUDA version for the card.

### How to reproduce the problem

Install InvokeAI on a Windows system with an RTX2060

### Additional context

Starting up...
Started Invoke process with PID: 30380
WARNING[XFORMERS]: Need to compile C++ extensions to use all xFormers features.
Please install xformers properly (see https://github.com/facebookresearch/xformers#installing-xformers)
Memory-efficient attention, SwiGLU, sparse and more won't be available.
Set XFORMERS_MORE_DETAILS=1 for more details
[2025-07-07 09:40:29,134]::[InvokeAI]::INFO --> Using torch device: NVIDIA GeForce RTX 2060
[2025-07-07 09:40:30,186]::[InvokeAI]::INFO --> cuDNN version: 90701
[2025-07-07 09:40:31,193]::[InvokeAI]::INFO --> Patchmatch initialized
[2025-07-07 09:40:31,729]::[InvokeAI]::INFO --> InvokeAI version 5.15.0
[2025-07-07 09:40:31,729]::[InvokeAI]::INFO --> Root directory = C:\Invoke

### Discord username

_No response_