This commit introduces a new diagnostics feature which is executed
when the app boots. When the app boots, the integrity of the PHP
symlinks are checked to ensure that all symlinks correctly link to
a valid PHP version. If any links to an incorrect PHP version,
then those outdated or incorrect symlinks will be removed.
For example, if `php@8.2` links to `../Cellar/php/8.3.0` then that is
an obvious reason for that symlink to be purged because it links to
the incorrect version. (This example behaviour has been noted in #270.)
This occurs prior to the rest of the startup process, so this way
no incorrect PHP versions can pop up in the version switcher, and
no incorrect PHP version is reported as being installed when
managing installed PHP versions.
In order to make this possible, I've added a new `sync()` method to the
Shellable protocol, which now should allow us to run shell commands
synchronously. Back to basics, as this was how *all* commands were
run in legacy versions of PHP Monitor.
The advantage here is that there is now a choice. Previously, you'd
have to use the `system()` helper that I added.
Usage of that helper is now discouraged, as is the synchronous
shell method, but it may be useful for some methods where waiting
for the outcome of the output is required.
(Important: the `system()` helper is still required when determining
what the preferred terminal is during the initialization of the
`Paths` class.)
The older version (8.2 in most cases) that becomes obsolete will also
be reinstalled and the app will attempt to switch to the last active
version as well. It is likely that PHP Monitor will have to repair
your older PHP installations after upgrading the `php` formula, but
this too should be a seamless process.
