[batch] remove redundant super class

All these classes inherit from `Resource` which is an `abc.ABC`.

batch/batch/cloud/azure/resources.py

@@ -14,7 +14,7 @@
 from .resource_utils import azure_disk_from_storage_in_gib, azure_disks_by_disk_type
 
 
-class AzureResource(Resource, abc.ABC):
+class AzureResource(Resource):
     pass
 
 

batch/batch/cloud/gcp/resources.py

@@ -14,7 +14,7 @@
 )
 
 
-class GCPResource(Resource, abc.ABC):
+class GCPResource(Resource):
     pass
 
 

batch/batch/resources.py

@@ -33,7 +33,7 @@ def to_dict(self) -> dict:
         raise NotImplementedError
 
 
-class StaticSizedDiskResourceMixin(Resource, abc.ABC):
+class StaticSizedDiskResourceMixin(Resource):
     storage_in_gib: int
 
     def to_quantified_resource(
@@ -44,47 +44,47 @@ def to_quantified_resource(
         return {'name': self.name, 'quantity': self.storage_in_gib * worker_fraction_in_1024ths}
 
 
-class DynamicSizedDiskResourceMixin(Resource, abc.ABC):
+class DynamicSizedDiskResourceMixin(Resource):
     @abc.abstractmethod
     def to_quantified_resource(
         self, cpu_in_mcpu: int, memory_in_bytes: int, worker_fraction_in_1024ths: int, external_storage_in_gib: int
     ) -> Optional[QuantifiedResource]:  # pylint: disable=unused-argument
         raise NotImplementedError
 
 
-class ComputeResourceMixin(Resource, abc.ABC):
+class ComputeResourceMixin(Resource):
     def to_quantified_resource(
         self, cpu_in_mcpu: int, memory_in_bytes: int, worker_fraction_in_1024ths: int, external_storage_in_gib: int
     ) -> Optional[QuantifiedResource]:  # pylint: disable=unused-argument
         del memory_in_bytes, worker_fraction_in_1024ths, external_storage_in_gib
         return {'name': self.name, 'quantity': cpu_in_mcpu}
 
 
-class VMResourceMixin(Resource, abc.ABC):
+class VMResourceMixin(Resource):
     def to_quantified_resource(
         self, cpu_in_mcpu: int, memory_in_bytes: int, worker_fraction_in_1024ths: int, external_storage_in_gib: int
     ) -> Optional[QuantifiedResource]:  # pylint: disable=unused-argument
         del cpu_in_mcpu, memory_in_bytes, external_storage_in_gib
         return {'name': self.name, 'quantity': worker_fraction_in_1024ths}
 
 
-class MemoryResourceMixin(Resource, abc.ABC):
+class MemoryResourceMixin(Resource):
     def to_quantified_resource(
         self, cpu_in_mcpu: int, memory_in_bytes: int, worker_fraction_in_1024ths: int, external_storage_in_gib: int
     ) -> Optional[QuantifiedResource]:  # pylint: disable=unused-argument
         del cpu_in_mcpu, worker_fraction_in_1024ths, external_storage_in_gib
         return {'name': self.name, 'quantity': memory_in_bytes // 1024 // 1024}
 
 
-class IPFeeResourceMixin(Resource, abc.ABC):
+class IPFeeResourceMixin(Resource):
     def to_quantified_resource(
         self, cpu_in_mcpu: int, memory_in_bytes: int, worker_fraction_in_1024ths: int, external_storage_in_gib: int
     ) -> Optional[QuantifiedResource]:  # pylint: disable=unused-argument
         del cpu_in_mcpu, memory_in_bytes, external_storage_in_gib
         return {'name': self.name, 'quantity': worker_fraction_in_1024ths}
 
 
-class ServiceFeeResourceMixin(Resource, abc.ABC):
+class ServiceFeeResourceMixin(Resource):
     def to_quantified_resource(
         self, cpu_in_mcpu: int, memory_in_bytes: int, worker_fraction_in_1024ths: int, external_storage_in_gib: int
     ) -> Optional[QuantifiedResource]:  # pylint: disable=unused-argument