Fix incorrectly generated code (elastic#205236)

## Summary

Fix build issues on
https://buildkite.com/elastic/kibana-es-ql-grammar-sync/builds/73

src/platform/packages/shared/kbn-esql-validation-autocomplete/scripts/generate_function_definitions.ts

@@ -386,7 +386,7 @@ import type { FunctionDefinition } from '../types';
 ${
   functionsType === 'scalar'
     ? `import type { ESQLFunction } from '@kbn/esql-ast';
-import { isLiteralItem } from '../../../../../shared/helpers';`
+import { isLiteralItem } from '../../shared/helpers';`
     : ''
 }