Merge pull request #8940 from SDA-SE/fix/api-docs-url

fix(api-docs): set url explicitly to an empty string

.changeset/sour-spies-hug.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-api-docs': patch
+---
+
+Using an explicitly empty string for the url argument ensures that the swagger UI does not run into undefined errors.

plugins/api-docs/src/components/OpenApiDefinitionWidget/OpenApiDefinition.tsx

@@ -148,7 +148,7 @@ export const OpenApiDefinition = ({ definition }: OpenApiDefinitionProps) => {
 
   return (
     <div className={classes.root}>
-      <SwaggerUI spec={def} deepLinking />
+      <SwaggerUI spec={def} url="" deepLinking />
     </div>
   );
 };