fix(upgrade): use 10 instead of MaxInt when rewriting query-concurrency

[danxmoran]

Closes #19958

MaxInt was conceptually as close as we could get to the old default of 0, but it caused problems in practice. Use the new default value of 10 instead.

• CHANGELOG.md updated with a link to the PR (not the Issue)
• Well-formatted commit messages
• Rebased/mergeable
• Tests pass
• http/swagger.yml updated (if modified Go structs or API)
• Feature flagged (if modified API)
• Documentation updated or issue created (provide link to issue/pr)
• Signed CLA (if not already signed)

[stuartcarnie]

Thanks for the fast turn around 🐎