dns/dnsmasq-devel: update to v2.91test10

Git history:

• efb8f10 2025-01-23 | Fix potential memory leak [Brian Haley]
• 6dbdf16 2025-01-24 | Move debian submodule to submodules/dnsmasq-debian. [Simon Kelley]
• 6e6a45a 2025-01-23 | Bump copyrights to 2025. [Simon Kelley]

MFH: 2025Q1