Adding single quotes around pip install in CONTRIBUTING.md

[rishabh-bhargava]

Before:

% pip install .[dev]
zsh: no matches found: .[dev]

After:

pip install '.[dev]'
Processing /private/tmp/autolabel
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
  Preparing metadata (pyproject.toml) ... done
Collecting loguru>=0.5.0
  Using cached loguru-0.7.0-py3-none-any.whl (59 kB)
Collecting rich>=13.3.5
  Using cached rich-13.4.2-py3-none-any.whl (239 kB)
Collecting scipy>=1.10.1
...

[DhruvaBansal00]

lgtm