Log netrc parsing error (#8364)
## Summary
Resolves #7685
## Test Plan
```console
$ echo "this is an invalid netrc" > .netrc
$ NETRC=.netrc cargo run -- pip install anyio --index-url https://pypi-proxy.fly.dev/basic-auth/simple --strict -v
DEBUG uv 0.4.24 (f4d5fba61 2024-10-19)
DEBUG Searching for default Python interpreter in system path or `py` launcher
DEBUG Found `cpython-3.11.2-windows-x86_64-none` at `D:\Projects\Rust\uv\.venv\Scripts\python.exe` (virtual environment)
DEBUG Using Python 3.11.2 environment at .venv
DEBUG Acquired lock for `.venv`
DEBUG At least one requirement is not satisfied: anyio
DEBUG Using request timeout of 30s
DEBUG Solving with installed Python version: 3.11.2
DEBUG Solving with target Python version: >=3.11.2
DEBUG Adding direct dependency: anyio*
DEBUG No cache entry for: https://pypi-proxy.fly.dev/basic-auth/simple/anyio/
WARN Error reading netrc file: parsing error: bad toplevel token 'this' (line 1) in the file '.netrc'
DEBUG Searching for a compatible version of anyio (*)
DEBUG No compatible version found for: anyio
× No solution found when resolving dependencies:
╰─▶ Because anyio was not found in the package registry and you require anyio, we can conclude that your
requirements are unsatisfiable.
hint: An index URL (https://pypi-proxy.fly.dev/basic-auth/simple) could not be queried due to a lack of valid
authentication credentials (401 Unauthorized).
DEBUG Released lock at `D:\Projects\Rust\uv\.venv\.lock`
error: process didn't exit successfully: `target\debug\uv.exe pip install anyio --index-url https://pypi-proxy.fly.dev/basic-auth/simple --strict -v` (exit code: 1)
```
