Restore test_build_sdist_relative_path_import to its former simple implementation.

setuptools/tests/test_build_meta.py

@@ -125,8 +125,8 @@ defns = [
 class TestBuildMetaBackend:
     backend_name = 'setuptools.build_meta'
 
-    def get_build_backend(self, **kwargs):
-        return BuildBackend(backend_name=self.backend_name, **kwargs)
+    def get_build_backend(self):
+        return BuildBackend(backend_name=self.backend_name)
 
     @pytest.fixture(params=defns)
     def build_backend(self, tmpdir, request):
@@ -334,11 +334,11 @@ class TestBuildMetaBackend:
             """)
     }
 
-    def test_build_sdist_relative_path_import(self, tmp_path):
-        build_files(self._relative_path_import_files, prefix=str(tmp_path))
-        build_backend = self.get_build_backend(cwd=tmp_path)
+    def test_build_sdist_relative_path_import(self, tmpdir_cwd):
+        build_files(self._relative_path_import_files)
+        build_backend = self.get_build_backend()
         with pytest.raises(ImportError, match="^No module named 'hello'$"):
-            build_backend.build_sdist(tmp_path / "temp")
+            build_backend.build_sdist("temp")
 
     @pytest.mark.parametrize('setup_literal, requirements', [
         ("'foo'", ['foo']),