The minimum libcurl was raised to 7.61.0 in #13259 to line up with RHEL 8, the oldest enterprise distribution still in support. The thing is, RHEL 8 and its rebuilds (Rocky, Alma, EL 8) don't actually ship 7.61.0 — they ship 7.61.1, and have done since the original 8.0 GA in May 2019 (curl-7.61.1-8.el8). The plain 7.61.0 point release was only the latest stable for about two months in 2018 before 7.61.1 superseded it, and I can't find a supported distribution that carries it. So moving the floor from 7.61.0 to 7.61.1 doesn't drop anything real; it just makes the requirement match the baseline it was already meant to represent.

There's a small concrete upside too. 7.61.1 is where curl/curl@d6cf930 landed, which fixed libcurl reporting success with no response (errno 0) when it needed to rewind an upload to resend it but couldn't. Before that fix the failure was silent; from 7.61.1 it surfaces properly as CURLE_SEND_FAIL_REWIND. Requiring 7.61.1 makes that behaviour consistent across every libcurl PHP can be built against. Moreover, in combination with #22230, this would allow a future version of Guzzle to by-pass some janky workaround code on PHP 8.6+ (and eventually remove that code... in like a decade when Guzzle can make PHP 8.6 the minimum version floor).