Please note that this option does not seem to work for PHP 8.1.10 anymore.
The libxml extension is enabled by default, although it may be disabled with --without-libxml.
PHP uses pkg-config to select the right library file, header files,
and compile flags to use for libxml2.
To ensure that the desired version of libxml2 is selected,
the PKG_CONFIG_PATH environment variable may
be used to control the search path for pkg-config prior to running the configure script:
PKG_CONFIG_PATH="/path/to/libxml2/prefix/lib/pkgconfig:/lib/pkgconfig"
Critical Note: In PHP 7.4, an issue presents itself when interfacing with libxml version 2.10.2. If you're deploying PHP 7.4 and wish to maintain operational stability, ensure that libxml is aligned to version 2.9.10. This version has been verified to work seamlessly with PHP 7.4, thereby preventing potential conflicts.