Disable PEAR by default

[alexmace]

I'd like to propose disabling the installation of PEAR with PHP, for a few reasons.

• PEAR really doesn't work well with multiple PHP versions - it can't manage it's dependencies properly based on the PHP version, leading to incompatibilities.
• It has been largely replacing in community usage by composer, which allow management of dependencies on a per project and per PHP version basis.
• It appears highly likely that PEAR will be deprecated in a forthcoming version of PHP and removed in PHP 8: https://wiki.php.net/rfc/deprecate-pear-include-composer
• PEAR itself is hosted on a single server, and when it is not available installation of PHP by this module fails. This bit us last year and resulted in us disabling pear in out usage.

So I would propose that this module, by default, does not include PEAR with PHP. A heira config would be added to allow the installation of it.

I can submit a PR for this if it is something we can do.

[jacobbednarz]

I'm in favour of this idea however removing PEAR by default would be a huge step. Instead, I'd rather drop it in with backwards compatibility and allow people to flip this off if they want to and then when upstream PHP drops it, we can just flip the default.

Does that make sense?