fix(backend): make preset migration not crash the system (#10966)

<!-- Clearly explain the need for these changes: -->
For those who develop blocks, they may or may not exist in the code at
the same time as the database.
> Create block in one branch, test, then move to another branch the
block is not in

This migration will prevent startup in that case.

### Changes 🏗️
Adds a try except around the migration
<!-- Concisely describe all of the changes made in this pull request:
-->

### Checklist 📋

#### For code changes:
- [x] I have clearly listed my changes in the PR description
- [x] I have made a test plan
- [x] I have tested my changes according to the test plan:
  <!-- Put your test plan here: -->
  - [x] Test that startup actually works

---------

Co-authored-by: Reinier van der Leer <pwuts@agpt.co>

autogpt_platform/backend/backend/integrations/webhooks/utils.py

@@ -168,38 +168,45 @@ async def migrate_legacy_triggered_graphs():
     n_migrated_webhooks = 0
 
     for graph in triggered_graphs:
-        if not ((trigger_node := graph.webhook_input_node) and trigger_node.webhook_id):
+        try:
+            if not (
+                (trigger_node := graph.webhook_input_node) and trigger_node.webhook_id
+            ):
+                continue
+
+            # Use trigger node's inputs for the preset
+            preset_credentials = {
+                field_name: creds_meta
+                for field_name, creds_meta in trigger_node.input_default.items()
+                if is_credentials_field_name(field_name)
+            }
+            preset_inputs = {
+                field_name: value
+                for field_name, value in trigger_node.input_default.items()
+                if not is_credentials_field_name(field_name)
+            }
+
+            # Create a triggered preset for the graph
+            await create_preset(
+                graph.user_id,
+                LibraryAgentPresetCreatable(
+                    graph_id=graph.id,
+                    graph_version=graph.version,
+                    inputs=preset_inputs,
+                    credentials=preset_credentials,
+                    name=graph.name,
+                    description=graph.description,
+                    webhook_id=trigger_node.webhook_id,
+                    is_active=True,
+                ),
+            )
+
+            # Detach webhook from the graph node
+            await set_node_webhook(trigger_node.id, None)
+
+            n_migrated_webhooks += 1
+        except Exception as e:
+            logger.error(f"Failed to migrate graph #{graph.id} trigger to preset: {e}")
             continue
 
-        # Use trigger node's inputs for the preset
-        preset_credentials = {
-            field_name: creds_meta
-            for field_name, creds_meta in trigger_node.input_default.items()
-            if is_credentials_field_name(field_name)
-        }
-        preset_inputs = {
-            field_name: value
-            for field_name, value in trigger_node.input_default.items()
-            if not is_credentials_field_name(field_name)
-        }
-
-        # Create a triggered preset for the graph
-        await create_preset(
-            graph.user_id,
-            LibraryAgentPresetCreatable(
-                graph_id=graph.id,
-                graph_version=graph.version,
-                inputs=preset_inputs,
-                credentials=preset_credentials,
-                name=graph.name,
-                description=graph.description,
-                webhook_id=trigger_node.webhook_id,
-                is_active=True,
-            ),
-        )
-        # Detach webhook from the graph node
-        await set_node_webhook(trigger_node.id, None)
-
-        n_migrated_webhooks += 1
-
     logger.info(f"Migrated {n_migrated_webhooks} node triggers to triggered presets")