Edit path when building sdist package

This patch changes the working directory from the temp to the project
when building sdist package.This resolves issues with relative paths
in configuration files.

cibuildwheel/__main__.py

@@ -160,7 +160,7 @@ def main() -> None:
         # This is now the new package dir
         args.package_dir = project_dir.resolve()
 
-        with chdir(temp_dir):
+        with chdir(project_dir):
             build_in_directory(args)
     finally:
         # avoid https://github.com/python/cpython/issues/86962 by performing