fix: allow google-cloud-documentai 3.x (#2237)

Author: parthea

packages/gapic-generator/gapic/templates/_pypi_packages.j2

@@ -11,7 +11,7 @@ Note: Set the minimum version for google-cloud-documentai to 2.0.0 which has sup
     ("google", "apps", "script", "type"): {"package_name": "google-apps-script-type", "lower_bound": "0.2.0", "upper_bound": "1.0.0dev"},
     ("google", "geo", "type"): {"package_name": "google-geo-type", "lower_bound": "0.1.0", "upper_bound": "1.0.0dev"},
     ("google", "identity", "accesscontextmanager", "v1"): {"package_name": "google-cloud-access-context-manager", "lower_bound": "0.1.2", "upper_bound": "1.0.0dev"},
-    ("google", "cloud", "documentai", "v1"): {"package_name": "google-cloud-documentai", "lower_bound": "2.0.0", "upper_bound": "3.0.0dev"},
+    ("google", "cloud", "documentai", "v1"): {"package_name": "google-cloud-documentai", "lower_bound": "2.0.0", "upper_bound": "4.0.0dev"},
     ("google", "cloud", "kms", "v1"): {"package_name": "google-cloud-kms", "lower_bound": "2.3.0", "upper_bound": "4.0.0dev"},
     ("google", "cloud", "osconfig", "v1"): {"package_name": "google-cloud-os-config", "lower_bound": "1.0.0", "upper_bound": "2.0.0dev"},
     ("google", "iam", "v1"): {"package_name": "grpc-google-iam-v1", "lower_bound": "0.12.4", "upper_bound": "1.0.0dev"},