Replace @flaky.flaky decorate with pytest marker

Use the `@pytest.mark.flaky` marker in place of the `@flaky.flaky`
decorator, to modernize the code and improve compatibility with other
plugins providing the feature such as `pytest-rerunfailures`.

Signed-off-by: Michał Górny <[email protected]>

Author: mgorny

tests/services/kernels/test_api.py

@@ -7,7 +7,6 @@
 import jupyter_client
 import pytest
 import tornado
-from flaky import flaky
 from jupyter_client.kernelspec import NATIVE_KERNEL_NAME
 from tornado.httpclient import HTTPClientError
 
@@ -257,7 +256,7 @@ async def test_kernel_handler_startup_error_pending(
         await jp_ws_fetch("api", "kernels", kid, "channels")
 
 
-@flaky
+@pytest.mark.flaky
 @pytest.mark.timeout(TEST_TIMEOUT)
 async def test_connection(jp_fetch, jp_ws_fetch, jp_http_port, jp_auth_header):
     # Create kernel

tests/services/kernels/test_execution_state.py

@@ -9,7 +9,6 @@
 
 import jupyter_client
 import pytest
-from flaky import flaky
 from tornado.httpclient import HTTPClientError
 from traitlets.config import Config
 
@@ -18,7 +17,7 @@
 MINIMUM_CONSISTENT_COUNT = 4
 
 
-@flaky
+@pytest.mark.flaky
 async def test_execution_state(jp_fetch, jp_ws_fetch):
     r = await jp_fetch("api", "kernels", method="POST", allow_nonstandard_methods=True)
     kernel = json.loads(r.body.decode())

tests/services/sessions/test_api.py

@@ -9,7 +9,6 @@
 import jupyter_client
 import pytest
 import tornado
-from flaky import flaky
 from jupyter_client.ioloop import AsyncIOLoopKernelManager
 from nbformat import writes
 from nbformat.v4 import new_notebook
@@ -505,7 +504,7 @@ async def test_modify_kernel_id(session_client, jp_fetch, jp_serverapp, session_
         assert kernel_list == [kernel]
 
 
-@flaky
+@pytest.mark.flaky
 @pytest.mark.timeout(TEST_TIMEOUT)
 async def test_restart_kernel(session_client, jp_base_url, jp_fetch, jp_ws_fetch, session_is_ready):
     # Create a session.

tests/test_terminal.py

@@ -7,7 +7,6 @@
 import warnings
 
 import pytest
-from flaky import flaky  # type:ignore[import-untyped]
 from tornado.httpclient import HTTPClientError
 from traitlets.config import Config
 
@@ -230,7 +229,7 @@ async def test_terminal_create_with_bad_cwd(jp_fetch, jp_ws_fetch):
     assert non_existing_path not in message_stdout
 
 
-@flaky
+@pytest.mark.flaky
 def test_culling_config(jp_server_config, jp_configurable_serverapp):
     app = jp_configurable_serverapp()
     terminal_mgr_config = app.config.ServerApp.TerminalManager
@@ -242,7 +241,7 @@ def test_culling_config(jp_server_config, jp_configurable_serverapp):
     assert terminal_mgr_settings.cull_interval == CULL_INTERVAL
 
 
-@flaky
+@pytest.mark.flaky
 async def test_culling(jp_server_config, jp_fetch):
     # POST request
     resp = await jp_fetch(