build: treat warnings as errors

Author: parthea

pytest.ini

@@ -0,0 +1,12 @@
+[pytest]
+filterwarnings =
+    # treat all warnings as errors
+    error
+    # Remove once https://github.com/protocolbuffers/protobuf/issues/12186 is fixed
+    ignore:.*custom tp_new.*in Python 3.14:DeprecationWarning
+    # Remove once https://github.com/dateutil/dateutil/issues/1314 is fixed
+    # dateutil is a dependency of pandas
+    ignore:datetime.datetime.utcfromtimestamp\(\) is deprecated:DeprecationWarning:dateutil.tz.tz
+    # Remove once https://github.com/googleapis/python-db-dtypes-pandas/issues/227 is fixed
+    ignore:.*any.*with datetime64 dtypes is deprecated and will raise in a future version:FutureWarning
+    ignore:.*all.*with datetime64 dtypes is deprecated and will raise in a future version:FutureWarning