Require Python 3.0+ in the templates

Author: vchudnov-g

gapic/ads-templates/noxfile.py.j2

@@ -11,8 +11,6 @@ import nox  # type: ignore
 # Add tests for Python 3.15 alpha1
 # https://peps.python.org/pep-0790/
 ALL_PYTHON = [
-    "3.7",
-    "3.8",
     "3.9",
     "3.10",
     "3.11",

gapic/ads-templates/setup.py.j2

@@ -63,8 +63,6 @@ setuptools.setup(
         "License :: OSI Approved :: Apache Software License",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
@@ -76,7 +74,7 @@ setuptools.setup(
     ],
     platforms="Posix; MacOS X; Windows",
     packages=packages,
-    python_requires=">=3.7",
+    python_requires=">=3.9",
     install_requires=dependencies,
     include_package_data=True,
     zip_safe=False,

gapic/templates/noxfile.py.j2

@@ -33,8 +33,6 @@ if os.path.isdir("samples"):
     FORMAT_PATHS.append("samples")
 
 ALL_PYTHON = [
-    "3.7",
-    "3.8",
     "3.9",
     "3.10",
     "3.11",

gapic/templates/setup.py.j2

@@ -89,8 +89,6 @@ setuptools.setup(
         "License :: OSI Approved :: Apache Software License",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
@@ -102,7 +100,7 @@ setuptools.setup(
     ],
     platforms="Posix; MacOS X; Windows",
     packages=packages,
-    python_requires=">=3.7",
+    python_requires=">=3.9",
     install_requires=dependencies,
     extras_require=extras,
     include_package_data=True,

gapic/templates/testing/constraints-3.7.txt.j2

@@ -1,4 +1,22 @@
 # -*- coding: utf-8 -*-
-{% block constraints %}
-{% include "testing/_default_constraints.j2" %}
-{% endblock %}
+{% from '_pypi_packages.j2' import pypi_packages %}
+# This constraints file is used to check that lower bounds
+# are correct in setup.py
+# List all library dependencies and extras in this file.
+# Pin the version to the lower bound.
+# e.g., if setup.py has "google-cloud-foo >= 1.14.0, < 2.0.0",
+# Then this file should have google-cloud-foo==1.14.0
+google-api-core==1.34.1
+google-auth==2.35.0
+# TODO(https://github.com/googleapis/gapic-generator-python/issues/2453)
+# Add the minimum supported version of grpcio to constraints files
+proto-plus==1.22.3
+protobuf==4.25.8
+{% for package_tuple, package_info in pypi_packages.items() %}
+{# Quick check to make sure `package_info.package_name` is not the package being generated so we don't circularly include this package in its own constraints file. #}
+{% if api.naming.warehouse_package_name != package_info.package_name %}
+{% if api.requires_package(package_tuple) %}
+{{ package_info.package_name }}=={{ package_info.lower_bound }}
+{% endif %}
+{% endif %}
+{% endfor %}