Fix several deprecation warnings

[kurtmckee]

Description of change

This change fixes several warnings thrown during test suite execution [recent CI run examples, see the first two warnings]:

DeprecationWarning: Call to deprecated close.
(Use aclose() instead) -- Deprecated since version 5.0.0.

In one case, the .close() usage is incorrect and needed to be updated. In another, the .close() call is deliberately testing deprecated usage and simply needed the pytest.deprecated_call() context manager added.

DeprecationWarning: 'asyncio.iscoroutinefunction' is deprecated
and slated for removal in Python 3.16; use inspect.iscoroutinefunction() instead

inspect.iscoroutinefunction() was added in Python 3.8 and can be safely switched to.

Pull Request check-list

• Do tests and lints pass with this change?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?
• Is there an example added to the examples folder (if applicable)?

[mkmkme]

Thanks! I've seen those warnings and meant to tackle them myself, but great to see your PR. If it doesn't break anything on the older Python versions, I don't see a reason for it not to be merged.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.39%. Comparing base (d3eb971) to head (794fd39).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #297      +/-   ##
==========================================
- Coverage   76.40%   76.39%   -0.02%     
==========================================
  Files         129      129              
  Lines       34065    34066       +1     
==========================================
- Hits        26029    26026       -3     
- Misses       8036     8040       +4     

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[kurtmckee]

There's more warnings to address, but ResourceWarnings typically require a bit more time to hunt down, so this was what I was able to tackle this morning. 👍

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Fixes deprecation warnings seen during the test suite run by updating deprecated async close usage and replacing the deprecated asyncio.iscoroutinefunction helper.

Changes:

• Replace asyncio.iscoroutinefunction() with inspect.iscoroutinefunction() in the asyncio connection logic.
• Update a test to use aclose() instead of the deprecated close().
• Wrap an intentional deprecated close() call in pytest.deprecated_call().

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
valkey/asyncio/connection.py	Switch coroutine function detection away from deprecated asyncio.iscoroutinefunction.
tests/test_asyncio/test_cwe_404.py	Update test cleanup to use aclose() to avoid deprecated close().
tests/test_asyncio/test_cluster.py	Explicitly assert the deprecation warning when calling deprecated close().

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[mkmkme]

Thanks again!