remove python setup.py build_ext --inplace from the github action and install instruction

Author: jeongyoonlee

.github/workflows/python-test.yaml

@@ -28,6 +28,5 @@ jobs:
             pip install --upgrade pip
             pip install --upgrade setuptools
             python -m pip install .[test]
-            python setup.py build_ext --inplace
       - name: Test with pytest
         run: pytest -vs tests/ --cov causalml/

.github/workflows/test-build-from-source.yml

@@ -70,7 +70,6 @@ jobs:
             pip install -U setuptools
             python -m pip install .${{ matrix.tf-label-pip}}
             python -m pip install .[test]
-            python setup.py build_ext --inplace
 
       - name: Test with pytest
         run: pytest -vs tests/ --cov causalml/

docs/installation.rst

@@ -73,7 +73,6 @@ Then:
     git clone https://github.com/uber/causalml.git
     cd causalml
     pip install .
-    python setup.py build_ext --inplace
 
 with ``tensorflow`` for ``DragonNet``: