[9.5] [CI] Fix Quick-checks flakiness: force unused_deps to run sequentially (#290536) - #290602

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: hmarr/auto-approve-action@f0939ea97e9205ef24d872e76833fa908a770363. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/