chore: update pytest.ini to latest state (#104)

## What's Changed

Updates pytest.ini to match how we have it set up for other repos.
Notably, we treat warnings as errors now.

Author: amoeba

go/validation/pytest.ini

@@ -19,3 +19,8 @@ xfail_strict = true
 
 markers =
     feature: test for a driver-specific feature
+
+filterwarnings =
+    error
+    ignore:record_property is incompatible with junit_family:pytest.PytestWarning
+    ignore:Cannot disable autocommit; conn will not be DB-API 2.0 compliant:adbc_driver_manager._lib.Warning