text: Title: DoH3 or HTTP3
  Body: **Motivation**
  We can utilize HTTP/3 in DoH implementation. Cloudflare, Google and NextDNS server already support this!
  
  <img width="1125" alt="Screenshot 2024-01-03 at 01 23 10" src="https://github.com/rthalley/dnspython/assets/125150101/a760e0c8-8553-4f65-a303-faa393aeef97">
  
  *NextDNS log*
  
  **Describe the solution you'd like.**
  Enable HTTP/3 in DoH by default, if not available, fallback to HTTP/2.
  