ci/update-other: tweak names

Author: MattSturgeon

.github/workflows/update-other.yml

@@ -10,20 +10,20 @@ permissions:
 
 jobs:
   update:
-    name: Trigger updates for nixvim's stable branches
+    name: Trigger update on ${{ matrix.branch }}
     runs-on: ubuntu-24.04-arm
     if: github.repository == 'nix-community/nixvim'
     strategy:
       matrix:
-        branches:
+        branch:
           - nixos-25.05
           - nixos-24.11
     steps:
-      - name: Update ${{ matrix.branches }}
+      - name: workflow dispatch
         env:
           GH_TOKEN: ${{ github.token }}
           repo: ${{ github.repository }}
-          branch: ${{ matrix.branches }}
+          branch: ${{ matrix.branch }}
         run: |
           gh --repo "$repo" workflow run \
             update.yml --ref "$branch"