fix: remove branch key that is not used

Author: OliverDudgeon

build-client/action.yaml

@@ -17,7 +17,6 @@ runs:
   - uses: actions/checkout@v4
     with:
       repository: InformaticsMatters/openapi-js-client-generator
-      branch: main
   - uses: actions/checkout@v4
     with:
       path: "./client"