feat: centralize mypy config

Author: chalmerlowe

mypy.ini

@@ -0,0 +1,94 @@
+[mypy]
+python_version = 3.14
+namespace_packages = True
+ignore_missing_imports = False
+
+# Helps mypy navigate the "google" namespace more reliably in 3.10+
+explicit_package_bases = True
+
+# Performance: reuse results from previous runs to speed up "nox"
+incremental = True
+
+exclude = (?x)(
+    ^third_party/
+  | tests/unit/resources/
+  | tests/unit/gapic/
+  )
+
+# TODO(https://github.com/googleapis/gapic-generator-python/issues/2563):
+# Dependencies that historically lacks py.typed markers
+[mypy-google.iam.*]
+ignore_missing_imports = True
+
+[mypy-google.type.*]
+ignore_missing_imports = True
+
+
+# ==============================================================================
+# PACKAGE-SPECIFIC OVERRIDES
+# ==============================================================================
+
+# --- google-cloud-core ---
+[mypy-google.protobuf.*]
+ignore_missing_imports = True
+
+# --- bigframes ---
+[mypy-cloudpickle.*]
+ignore_missing_imports = True
+[mypy-flask]
+ignore_missing_imports = True
+[mypy-pydata_google_auth]
+ignore_missing_imports = True
+[mypy-google.colab]
+ignore_missing_imports = True
+[mypy-pytz]
+ignore_missing_imports = True
+[mypy-pyarrow.*]
+ignore_missing_imports = True
+[mypy-ibis.*]
+ignore_missing_imports = True
+[mypy-ipywidgets]
+ignore_missing_imports = True
+[mypy-google.cloud.pubsub]
+ignore_missing_imports = True
+[mypy-google.cloud.bigtable]
+ignore_missing_imports = True
+[mypy-anywidget]
+ignore_missing_imports = True
+
+# --- google-cloud-bigtable ---
+[mypy-google.cloud.bigtable.*]
+check_untyped_defs = True
+warn_unreachable = True
+disallow_any_generics = True
+ignore_errors = True
+
+[mypy-google.cloud.bigtable.data.*]
+ignore_errors = False
+
+[mypy-grpc.*]
+ignore_missing_imports = True
+[mypy-google.auth.*]
+ignore_missing_imports = True
+[mypy-google.longrunning.*]
+ignore_missing_imports = True
+[mypy-google.oauth2.*]
+ignore_missing_imports = True
+[mypy-google.rpc.*]
+ignore_missing_imports = True
+[mypy-proto.*]
+ignore_missing_imports = True
+[mypy-pytest]
+ignore_missing_imports = True
+
+# --- google-cloud-datastore ---
+[mypy-google.cloud.datastore._app_engine_key_pb2]
+ignore_errors = True
+
+# TODO(https://github.com/googleapis/gapic-generator-python/issues/2410):
+# Remove once this generator bug is fixed
+[mypy-google.cloud.datastore_v1.services.datastore.async_client]
+ignore_errors = True
+
+[mypy-google.cloud.datastore_v1.services.datastore.client]
+ignore_errors = True