WIP: Debug ResourceWarnings BufferedRandom
xref #44844

might be good to have a test whether `lsof` finds ResourceWarnings (the psutil doesn't seem to find them/some of them).

```py
with pytest.raises(...):
    with check_bufferedrandom_resourcewarning():
        foo = open("foo")
foo.close()
```

Specifically enabling ResourceWarnings (usually disabled by default) seemed to work well for me in #39047: adding `always::ResourceWarning` to `filterwarnings` in setup.cfg. > might be good to have a test whether `lsof` finds ResourceWarnings (the psutil doesn't seem to find them/some of them).
> 
> ```python
> with pytest.raises(...):
>     with check_bufferedrandom_resourcewarning():
>         foo = open("foo")
> foo.close()
> ```
> 
> Specifically enabling ResourceWarnings (usually disabled by default) seemed to work well for me in #39047: adding `always::ResourceWarning` to `filterwarnings` in setup.cfg.

Yeah might do this in a follow up. Ideally just checking which tests open up new OS-level file handles. Apparently the `BufferedResourceWarning` opens it up at n=10 Closing in favor of https://github.com/pandas-dev/pandas/pull/45073