chore(bigquery): centralize mypy config for bigquery (#17640)

* Relies on a centralized `mypy.ini` file at the root of the repository
to consolidate all shared and package-specific mypy exceptions.
* Deletes the individual `mypy.ini` files from handwritten libraries,
establishing the root configuration as the source of truth.
* Refactored their `noxfile.py` files to define `MYPY_CONFIG_FILE`
dynamically and standardized their `session.run("mypy", ...)`
invocations.

Related to: PR #17409 and PR #17641

> [!note]
> all three PRs rely on the same centralized mypy.ini config. So you may
see some minor edits in the main config that are applicable to packages
in one of the other PRs. This will have no effect on those packages
until their noxfiles are updated to begin using the new centralized
config.

Author: chalmerlowe

mypy.ini

@@ -14,7 +14,6 @@ exclude = (?x)(
   | (^|/)tests/unit/gapic/
   )
 
-
 # ==============================================================================
 # GLOBAL THIRD-PARTY & SHARED LIBRARY IGNORES
 # ==============================================================================
@@ -28,13 +27,7 @@ ignore_missing_imports = True
 [mypy-flask]
 ignore_missing_imports = True
 
-[mypy-google.auth.*]
-ignore_missing_imports = True
-
-[mypy-google.cloud.bigtable]
-ignore_missing_imports = True
-
-[mypy-google.cloud.pubsub]
+[mypy-google.api.*]
 ignore_missing_imports = True
 
 [mypy-google.colab]
@@ -61,6 +54,9 @@ ignore_missing_imports = True
 [mypy-grpc.*]
 ignore_missing_imports = True
 
+[mypy-grpc_status]
+ignore_missing_imports = True
+
 [mypy-ibis.*]
 ignore_missing_imports = True
 
@@ -86,8 +82,18 @@ ignore_missing_imports = True
 # ==============================================================================
 # PACKAGE-SPECIFIC OVERRIDES & EXCEPTIONS
 # ==============================================================================
+# --- bigframes ---
+[mypy-bigframes_vendored.*]
+ignore_errors = True
+
+# --- google-auth ---
+[mypy-google.auth.*]
+ignore_missing_imports = True
 
 # --- google-cloud-bigtable ---
+[mypy-google.cloud.bigtable]
+ignore_missing_imports = True
+
 [mypy-google.cloud.bigtable.*]
 ignore_errors = True
 
@@ -97,4 +103,26 @@ warn_unreachable = True
 disallow_any_generics = True
 ignore_errors = False
 
+[mypy-google.cloud.bigtable_admin.*]
+ignore_errors = True
+
+[mypy-google.cloud.bigtable_admin_v2.*]
+ignore_errors = True
+
+[mypy-google.cloud.bigtable_v2.*]
+ignore_errors = True
 
+# --- google-cloud-datastore ---
+[mypy-google.cloud.datastore.*]
+ignore_missing_imports = True
+
+[mypy-google.cloud.datastore._app_engine_key_pb2]
+ignore_errors = True
+
+# --- google-cloud-firestore ---
+[mypy-google.cloud.firestore.*]
+check_untyped_defs = True
+
+# --- google-cloud-pubsub ---
+[mypy-google.cloud.pubsub]
+ignore_missing_imports = True

packages/google-cloud-bigquery/mypy.ini

@@ -41,6 +41,17 @@
 ALL_PYTHON = ["3.10", "3.11", "3.12", "3.13", "3.14"]
 UNIT_TEST_PYTHON_VERSIONS = ALL_PYTHON
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
+# Path to the centralized mypy configuration file at the repository root.
+# Search upwards to support running nox from both monorepo packages and integration test goldens.
+MYPY_CONFIG_FILE = next(
+    (
+        str(p / "mypy.ini")
+        for p in CURRENT_DIRECTORY.parents
+        if (p / "mypy.ini").exists()
+    ),
+    str(CURRENT_DIRECTORY.parent.parent / "mypy.ini"),
+)
+
 
 SYSTEM_TEST_PYTHON_VERSIONS = UNIT_TEST_PYTHON_VERSIONS
 
@@ -215,7 +226,13 @@ def mypy(session):
     )
     session.run("python", "-m", "pip", "freeze")
     with log_package_context(session):
-        session.run("mypy", "-p", "google", "--show-traceback")
+        session.run(
+            "mypy",
+            f"--config-file={MYPY_CONFIG_FILE}",
+            "-p",
+            "google",
+            "--show-traceback",
+        )
 
 
 @nox.session(python=SYSTEM_TEST_PYTHON_VERSIONS)