Update .github/workflows/librarian_library_generation.yaml

Co-authored-by: Min Zhu <zhumin@google.com>

Author: sofisl

.github/workflows/librarian_library_generation.yaml

@@ -11,7 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-name: Librarian library generation upon generation config change through pull requests
+name: Librarian generate diff check on pull requests
 on:
   pull_request: