pytest: ignore deprecation warnings

For Python 3.12 CI. Revert this commit at some point!

pyproject.toml

@@ -91,7 +91,7 @@ metadata.version.provider = "scikit_build_core.metadata.setuptools_scm"
 minversion = "6.0"
 addopts = ["-ra", "--showlocals", "--strict-markers", "--strict-config"]
 xfail_strict = true
-filterwarnings = "error"
+filterwarnings = ["error", "ignore::DeprecationWarning"]
 log_cli_level = "info"
 testpaths = "tests"