Fix wheel build

Author: WardBrian

.github/workflows/main.yml

@@ -58,7 +58,7 @@ jobs:
 
       - name: Install dependencies (python)
         run: |
-          python -m pip install --upgrade pip wheel
+          python -m pip install --upgrade pip wheel build
           pip install -r requirements.txt
           pip install -r requirements-test.txt
           pip install codecov
@@ -71,7 +71,7 @@ jobs:
           mypy cmdstanpy
 
       - name: Build wheel
-        run: python setup.py bdist_wheel
+        run: python -m build
 
       - name: Install wheel (Linux, macOS)
         if: matrix.os != 'windows-latest'