SourceHut uses a foss bot protection tool called `go-away` (which I can
recommend BTW). It blocks common crawler user agents, such as the standard
Firefox user agent. Hence, we're now using our custom SearXNG user agent to
clarify we're not a crawler.
Closes: https://github.com/searxng/searxng/issues/5270
Co-authored-by: Markus Heiser <markus.heiser@darmarit.de>
