Set graph version on branch creation

Author: gmazoyer

backend/infrahub/core/branch/models.py

@@ -6,9 +6,8 @@
 from pydantic import Field, field_validator
 
 from infrahub.core.branch.enums import BranchStatus
-from infrahub.core.constants import (
-    GLOBAL_BRANCH_NAME,
-)
+from infrahub.core.constants import GLOBAL_BRANCH_NAME
+from infrahub.core.graph import GRAPH_VERSION
 from infrahub.core.models import SchemaBranchHash  # noqa: TC001
 from infrahub.core.node.standard import StandardNode
 from infrahub.core.query import QueryType
@@ -262,6 +261,10 @@ def get_branches_and_times_for_range(
 
         return start, end
 
+    async def create(self, db: InfrahubDatabase) -> bool:
+        self.graph_version = GRAPH_VERSION
+        return await super().create(db=db)
+
     async def delete(self, db: InfrahubDatabase) -> None:
         if self.is_default:
             raise ValidationError(f"Unable to delete {self.name} it is the default branch.")