feat(generator): introduce MYPY_CONFIG_FILE constant in templates

Author: chalmerlowe

mypy.ini

@@ -1,5 +1,4 @@
 [mypy]
-python_version = 3.14
 namespace_packages = True
 ignore_missing_imports = False
 

packages/gapic-generator/gapic/ads-templates/noxfile.py.j2

@@ -3,10 +3,16 @@
 {% block content %}
 
 import os
+import pathlib
 
 import nox  # type: ignore
 
 
+CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
+# Path to the centralized mypy configuration file at the repository root.
+MYPY_CONFIG_FILE = str(CURRENT_DIRECTORY.parent.parent / "mypy.ini")
+
+
 # TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
 # Add tests for Python 3.15 alpha1
 # https://peps.python.org/pep-0790/
@@ -44,7 +50,7 @@ def mypy(session):
     session.install('.')
     session.run(
         'mypy',
-        "--config-file=../../mypy.ini",
+        f"--config-file={MYPY_CONFIG_FILE}",
         {% if api.naming.module_namespace %}
         '{{ api.naming.module_namespace[0] }}',
         {% else %}

packages/gapic-generator/gapic/templates/noxfile.py.j2

@@ -40,6 +40,8 @@ DEFAULT_PYTHON_VERSION = "3.14"
 PREVIEW_PYTHON_VERSION = "3.14"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
+# Path to the centralized mypy configuration file at the repository root.
+MYPY_CONFIG_FILE = str(CURRENT_DIRECTORY.parent.parent / "mypy.ini")
 
 if (CURRENT_DIRECTORY / "testing").exists():
     LOWER_BOUND_CONSTRAINTS_FILE = (
@@ -101,7 +103,7 @@ def mypy(session):
     session.install(".")
     session.run(
         "mypy",
-        "--config-file=../../mypy.ini",
+        f"--config-file={MYPY_CONFIG_FILE}",
         "-p",
         {% if api.naming.module_namespace %}
         "{{ api.naming.module_namespace[0] }}",