workflows: run update_releases on release-25.4

Epic: None
Release note: None

Author: dodeca12

.github/workflows/update_releases.yaml

@@ -32,6 +32,7 @@ jobs:
           - "release-24.3"
           - "release-25.2"
           - "release-25.3"
+          - "release-25.4"
     name: Update pkg/testutils/release/cockroach_releases.yaml on ${{ matrix.branch }}
     runs-on: ubuntu-latest
     steps: