Change setup script to use pip install instead of setup.py develop (#…

…7756)

Using `python setup.py develop` did not manage to install the required dependencies.
This updates `script/setup` to use `pip install -e .` instead in order to resolve the required dependencies.

script/setup

@@ -7,4 +7,5 @@ set -e
 cd "$(dirname "$0")/.."
 git submodule init
 script/bootstrap
-python3 setup.py develop
+
+pip3 install -e .