Return a default value if address resolution fails

[penguinpee]

If getaddrinfo() fails for whatever reason, return the default
loopback address instead. This allows running tests on systems
that are otherwise not connected to a network.

[penguinpee]

Fedora's build environment has always been restricted with regards to network. Recently, I noticed address resolution no longer working. That impacted the entire test suite, while the loopback adapter remains available.

It turns out this builds on the work of a fellow Fedorian (#8712). The warning message should allow for dask's tests to pass (currently testing), which already has "ignore:Couldn't detect a suitable IP address:RuntimeWarning:distributed", in pytest.filterwarnings.

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

    27 files  ±0      27 suites  ±0   11h 3m 15s ⏱️ - 3m 59s
 4 101 tests ±0   3 987 ✅ +2    112 💤 ±0  2 ❌  - 2 
51 413 runs  ±0  49 112 ✅ +3  2 297 💤  - 1  4 ❌  - 2 

For more details on these failures, see this check.

Results for commit a9f2f39. ± Comparison against base commit 3f17ddb.

[jacobtomlinson]

This looks reasonable to me. The CI failures appear to be unrelated.