hdfs: enable mocked hdfs tests by default (#6766)

tests/conftest.py

@@ -19,7 +19,8 @@ REMOTES = {
     "azure": False,
     "gdrive": False,
     "gs": False,
-    "hdfs": False,
+    "hdfs": True,
+    "real_hdfs": False,
     "http": True,
     "oss": False,
     "s3": False,

tests/remotes/hdfs.py

@@ -73,7 +73,7 @@ class HDFS(Base, URLInfo):  # pylint: disable=abstract-method
 
 @pytest.fixture(scope="session")
 def hadoop(test_config):
-    test_config.requires("hdfs")
+    test_config.requires("real_hdfs")
 
     if sys.version_info >= (3, 10):
         pytest.skip("pyarrow is not available for 3.10 yet.")