Bumps the minimum required libcurl version to 7.61.0.
Please also see #4917, which bumped minimum libcurl version to the current >= 7.29.0.
This bumps the minimum requirement to Curl 7.61.0 (released 2018 Sept).
Ubuntu, Debian, RHEL, and RHEL derivatives have major and LTS version bumps this year. Following are the
libcurl-dev/libcurl-devel versions available in the oldest supported (LTS or otherwise) in major OSs.
- Debian buster: [7.64](https://packages.debian.org/buster/libcurl4-openssl-dev)
- Ubuntu 20.04: [7.68](https://packages.ubuntu.com/focal/libcurl-dev)
- CentOS/RHEL 7: 7.29
- RHEL 8/Rocky 8/EL 8: 7.61
- Fedora 38: 7.87
RHEL/CentOS 7 reaches EOL mid 2024, so for PHP 8.4 scheduled towards the end of this year, we can safely
bump the minimum libcurl version.
7.61.0 was selected as the new minimum because RHEL and derivatives have libcurl-devel version 7.61. RHEL 8 is
a current and supported RHEL version.
We have bumped the libcurl requirement to 7.29.0 in PHP 8.1,
but the function declarations in the stubs were still conditional
on the curl version. Drop them to make it more obvious that these
functions are always available.
While the function name starts with curl_multi_*, the function
actually accepts a CurlHandle. As such, it should also use just
$handle as the parameter name.
Closes GH-6435.
