sync-diff-inspector: add PROCESS permission when upstream and downstream are TiDB (#21253)#21254

ti-chi-bot[bot] merged 1 commit intopingcap:release-8.1pingcap/docs-cn:release-8.1from

ti-chi-bot:cherry-pick-21253-to-release-8.1ti-chi-bot/docs-cn:cherry-pick-21253-to-release-8.1Copy head branch name to clipboard