fix(workflow): validate recordFilter operands in Find Records action before executing filter conversion

https://sonarly.com/issue/31353?type=bug

When a workflow's Find Records action contains a RELATION-type filter with the operand `EQUAL_TO`, the workflow executor crashes with an unhandled error: `Error: Unknown operand EQUAL_TO for RELATION filter`. The operand `EQUAL_TO` has never existed in the Twenty codebase — it is not present in `ViewFilterOperand`, `ViewFilterOperandDeprecated`, or anywhere in git history. The value was injected into a persisted workflow step's settings, bypassing the frontend UI (which correctly restricts RELATION operands to IS, IS_NOT, IS_EMPTY, IS_NOT_EMPTY). This was possible because the Zod validation schema for Find Records action settings uses `z.array(z.any())` for `recordFilters`, performing zero validation on filter operand values. At execution time, `turnRecordFilterIntoRecordGqlOperationFilter` encounters the unrecognized operand in the RELATION case's switch statement and throws, killing the entire workflow run.

Fix: Changed the RELATION filter's `default` case in `turnRecordFilterIntoRecordGqlOperationFilter` from `throw new Error(...)` to `return;` (returning `undefined`).

This is the exact same fix pattern applied in commit aba5c93a6f for the TEXT filter type. The function's return type is `RecordGqlOperationFilter | undefined`, and all callers in `computeRecordGqlOperationFilter` already filter results with `.filter(isDefined)`. Returning `undefined` gracefully skips the unrecognized operand instead of crashing the workflow execution.

When a workflow's Find Records action has a RELATION filter with an invalid operand like `EQUAL_TO` (which never existed in the codebase and was injected via API/integration), the filter is now silently skipped rather than killing the entire workflow run. The workflow continues executing with the remaining valid filters.

The deeper issue — the permissive `z.array(z.any())` Zod schema in `find-records-action-settings-schema.ts` that allows invalid operands to be persisted — remains as a separate improvement opportunity. This fix addresses the immediate user-facing crash at the execution layer.

packages/twenty-shared/src/utils/filter/turnRecordFilterIntoGqlOperationFilter.ts

@@ -559,9 +559,7 @@ export const turnRecordFilterIntoRecordGqlOperationFilter = ({
           };
         }
         default:
-          throw new Error(
-            `Unknown operand ${recordFilter.operand} for ${filterType} filter`,
-          );
+          return;
       }
     }
     case 'CURRENCY': {