qapi: Add some pylint ignores

This restores the linting baseline in QAPI.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20250604200354.459501-2-jsnow@redhat.com
diff --git a/scripts/qapi/backend.py b/scripts/qapi/backend.py
index 14e60aa6..49ae6ec 100644
--- a/scripts/qapi/backend.py
+++ b/scripts/qapi/backend.py
@@ -13,6 +13,7 @@
 
 
 class QAPIBackend(ABC):
+    # pylint: disable=too-few-public-methods
 
     @abstractmethod
     def generate(self,
@@ -36,6 +37,7 @@ def generate(self,
 
 
 class QAPICBackend(QAPIBackend):
+    # pylint: disable=too-few-public-methods
 
     def generate(self,
                  schema: QAPISchema,