Use a different env flag to make tests dir available inside the temporary test env.

Author: tanujjain

.github/workflows/build_wheels.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Build wheels
         uses: pypa/[email protected]
         env:
-          CIBW_TEST_SOURCES: "tests"
+          CIBW_BEFORE_TEST: "cp -r {project}/tests {package}/"
           CIBW_TEST_COMMAND: "ls -R && pwd && python -m pytest -v tests/" # "pytest tests/"
           CIBW_TEST_REQUIRES: pytest pytest-cov pytest-mock codecov
           CIBW_SKIP: cp36-* cp37-* cp38-* cp313-* pp* *-musllinux* *-manylinux_i686