fix(filler): fix shared-pre-state generation (#1738)

Author: marioevz

src/ethereum_test_fixtures/shared_alloc.py

@@ -30,8 +30,10 @@ class SharedPreStateGroup(CamelModel):
     fork: Fork = Field(..., alias="network")
     pre: Alloc
 
-    def __model_post_init__(self) -> None:
+    def model_post_init(self, __context):
         """Post-init hook to ensure pre is not None."""
+        super().model_post_init(__context)
+
         self.pre = Alloc.merge(
             Alloc.model_validate(self.fork.pre_allocation_blockchain()),
             self.pre,
@@ -56,12 +58,9 @@ def to_file(self, file: Path) -> None:
                         f.read()
                     )
                     for account in previous_shared_pre_state_group.pre:
-                        if account in self.pre:
-                            raise ValueError(
-                                f"Account {account} already exists in shared pre-allocation"
-                            )
-                        self.pre[account] = previous_shared_pre_state_group.pre[account]
-                        self.pre_account_count += 1
+                        if account not in self.pre:
+                            self.pre[account] = previous_shared_pre_state_group.pre[account]
+                    self.pre_account_count += previous_shared_pre_state_group.pre_account_count
                     self.test_count += previous_shared_pre_state_group.test_count
                     self.test_ids.extend(previous_shared_pre_state_group.test_ids)