Disk space check before download/installation

This probably applies both to the temp download folder and also to the target installation disk.
```
Deleting existing virtual environment...
Creating virtual environment...
> C:\Users\user\AppData\Local\Temp\2tHK8V6PQNi8BAls37RH9oI97Ms\resources\bin\uv.exe venv --relocatable --prompt invoke --python 3.11 --python-preference only-managed K:\AI\InvokeAI\.venv
Using CPython 3.11.11
Creating virtual environment at: K:\AI\InvokeAI\.venv
Activate with: K:\AI\InvokeAI\.venv\Scripts\activate
Installing invokeai package...
> C:\Users\user\AppData\Local\Temp\2tHK8V6PQNi8BAls37RH9oI97Ms\resources\bin\uv.exe pip install --python 3.11 --python-preference only-managed invokeai[xformers]==v5.9.1 --force-reinstall --compile-bytecode --index=https://download.pytorch.org/whl/cu124
Resolved 169 packages in 2.08s
× Failed to download `torch==2.4.1+cu124`
├─▶ Failed to extract archive
╰─▶ failed to write to file
`C:\Users\user\AppData\Local\uv\cache\.tmpKcFtn6\torch/lib/dnnl.lib`:
There is not enough space on the disk. (os error 112)
help: `torch` (v2.4.1+cu124) was included because `invokeai` (v5.9.1)
depends on `torch`
Failed to install invokeai python package: Process exited with code 1
```
FWIW this also broke my old installation, which wasn't recognized anymore afterwards.