Delete workflow step (#7373)

- Allows the deletion of triggers and steps in workflows. If the
workflow can not be edited right now, we create a new draft version.
- The workflow right drawer can now render nothing. It's necessary to
behave that way because a deleted step will still be displayed for a
short amount of time in the drawer. The drawer will be filled with blank
content when it disappears.


https://github.com/user-attachments/assets/abd5184e-d3db-4fe7-8870-ccc78ff23d41

Closes #7057

packages/twenty-front/src/modules/workflow/components/RightDrawerWorkflowEditStepContent.tsx

@@ -7,7 +7,7 @@ import { useUpdateWorkflowVersionTrigger } from '@/workflow/hooks/useUpdateWorkf
 import { workflowSelectedNodeState } from '@/workflow/states/workflowSelectedNodeState';
 import { WorkflowWithCurrentVersion } from '@/workflow/types/Workflow';
 import { assertUnreachable } from '@/workflow/utils/assertUnreachable';
-import { findStepPositionOrThrow } from '@/workflow/utils/findStepPositionOrThrow';
+import { findStepPosition } from '@/workflow/utils/findStepPosition';
 import { useRecoilValue } from 'recoil';
 import { isDefined } from 'twenty-ui';
 
@@ -43,10 +43,13 @@ const getStepDefinitionOrThrow = ({
     );
   }
 
-  const selectedNodePosition = findStepPositionOrThrow({
+  const selectedNodePosition = findStepPosition({
     steps: currentVersion.steps,
     stepId: stepId,
   });
+  if (!isDefined(selectedNodePosition)) {
+    return undefined;
+  }
 
   return {
     type: 'action',
@@ -76,6 +79,9 @@ export const RightDrawerWorkflowEditStepContent = ({
     stepId: workflowSelectedNode,
     workflow,
   });
+  if (!isDefined(stepDefinition)) {
+    return null;
+  }
 
   switch (stepDefinition.type) {
     case 'trigger': {