fix: ignore vendor directories

Closes #2673

lib/config/definitions.js

@@ -989,6 +989,7 @@ const options = [
     type: 'json',
     default: {
       fileMatch: ['(^|/)go.mod$'],
+      ignorePath: ['**/vendor/**'],
     },
     mergeable: true,
   },
@@ -1137,6 +1138,7 @@ const options = [
     type: 'json',
     default: {
       fileMatch: ['(^|\\/)([\\w-]*)composer.json$'],
+      ignorePath: ['**/vendor/**'],
     },
     mergeable: true,
     cli: false,