Remove unnecessary build step

tox builds it anyway

Author: horgh

.github/workflows/address-sanitizer.yml

@@ -32,8 +32,5 @@ jobs:
               python -m pip install --upgrade pip
               pip install tox tox-gh-actions
 
-      - name: Build
-        run: python setup.py build
-
       - name: Test with tox
         run: MM_FORCE_EXT_TESTS=1 tox