Show hint when permission denied encountered during system package install

[zanieb]

~: uv pip install --system Pillow
Using Python 3.12.8 environment at: /usr
Resolved 1 package in 103ms
error: Failed to install: pillow-11.1.0-cp312-cp312-manylinux_2_28_x86_64.whl (pillow==11.1.0)
  Caused by: failed to create directory `/usr/local/lib64/python3.12/site-packages/`: Permission denied (os error 13)

We should hint what to do here, e.g.,

hint: It looks like you do not have permissions to write to the system Python environment. Consider creating a virtual environment (uv venv) then installing the package or installing it in an isolated tool environment (uv tool install).

We could probably be smart, like only hint a tool install if the package has entry points.