Update asyncio/Tornado

[hoxbro]

make_current deprecation was reverted in Python and will not give a warning in Tornado 6.3 and forward (tornadoweb/tornado#3216).

The change in conftest.py is to avoid this warning, though I'm unsure if it is the right way.

  /home/shh/miniconda3/envs/holoviz/lib/python3.10/site-packages/tornado/ioloop.py:265: DeprecationWarning: There is no current event loop
    loop = asyncio.get_event_loop()

[codecov]

Codecov Report

Merging #4510 (47b1141) into main (c9702ee) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #4510      +/-   ##
==========================================
+ Coverage   82.32%   82.35%   +0.02%     
==========================================
  Files         243      243              
  Lines       35579    35585       +6     
==========================================
+ Hits        29292    29305      +13     
+ Misses       6287     6280       -7     

Flag	Coverage Δ
ui-tests	35.88% <100.00%> (+0.02%)	⬆️
unitexamples-tests	74.27% <100.00%> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
panel/io/server.py	74.86% <100.00%> (ø)
panel/tests/conftest.py	89.62% <100.00%> (+0.26%)	⬆️
panel/io/state.py	70.56% <0.00%> (+0.17%)	⬆️
panel/reactive.py	80.72% <0.00%> (+0.37%)	⬆️
panel/io/reload.py	73.91% <0.00%> (+2.17%)	⬆️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[philippjfr]

So I'm not 100% convinced we should actually make this change. Each thread should get its own event loop so it makes sense to me that we should use make_current=False in the IOLoop constructor and then have the thread start the event loop. Then again my mental model of this may not be 100% correct.

[philippjfr]

For the time being I'm going to keep the current approach. It seems more correct to me for the thread to start the event loop.