gh-144851: Fix __lazy_import__ crash with user-defined filters

[johnslavik]

Writing a test shortly, still in progress!

• Issue: __lazy_import__ crashes with user-defined filters #144851

[johnslavik]

Skipping news as this is still unreleased.

[johnslavik]

Hold on, this flow is more complicated than I thought...

[johnslavik]

OK, it's fine. All paths are good. 👍🏽

EDIT: I'm not sure we run all tests in CI. I'm adding a test to test the test.

[johnslavik]

We're not running test_lazy_imports in CI. I'm not sure if this is intended. I'll investigate further outside of this PR.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Debian root 3.x (tier-1) has failed when building commit 8bcb3ea.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/345/builds/13534) and take a look at the build logs.
4. Check if the failure is related to this commit (8bcb3ea) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/345/builds/13534

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/support/__init__.py", line 947, in gc_collect
gc.collect()
~~~~~~~~~~^^ResourceWarning: unclosed file <_io.FileIO name=13 mode='wb' closefd=True>