fix(plugins/catalog-backend-module-backstage-openapi): do not route request through external url but rather the internal one

Signed-off-by: secustor <sebastian@poxhofer.at>

.changeset/hungry-suns-hope.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend-module-backstage-openapi': patch
+---
+
+Use direct access of openapi.json files and not external route

plugins/catalog-backend-module-backstage-openapi/src/InternalOpenApiDocumentationProvider.ts

@@ -122,7 +122,7 @@ const loadSpecs = async ({
 }) => {
   const specs: OpenAPIObject[] = [];
   for (const pluginId of plugins) {
-    const url = await discovery.getExternalBaseUrl(pluginId);
+    const url = await discovery.getBaseUrl(pluginId);
     const openApiUrl = getOpenApiSpecRoute(url);
     const { token } = await auth.getPluginRequestToken({
       onBehalfOf: await auth.getOwnServiceCredentials(),