Fix tests (#8908)

Ref #8886

Author: stsewd

readthedocs/projects/tests/test_build_tasks.py

@@ -466,7 +466,7 @@ def test_build_commands_executed(self, load_yaml_config):
                 'install',
                 '--upgrade',
                 '--no-cache-dir',
-                'pip<=21.3.1',
+                'pip',
                 'setuptools<58.3.0',
                 bin_path=mock.ANY,
                 cwd=mock.ANY,