Admin checks fixes and improvements

[dregad]

Bug fixes:

• [x] #34910: Fatal error in Admin Checks when using invalid FileInfo magic database
• [x] #34911: Admin checks: fatal error if PHP database extension is not available

Enhancement / feature:

• [ ] #33012: Don't abort Admin Checks after first failure unless it's critical
• [x] #34909: Admin checks: unsupported version checks using endoflife.date

Code cleanup and cosmetic changes:

• [x] #34912: Admin checks: minor improvement to output messages
• [x] #34914: Remove admin check for obsolete register_long_arrays php.ini directive

[dregad]

@vboctor @atrol I marked the PR as draft because I'm planning to add the fix for #33012.

What has been committed so far is pretty much ready, if you want to review & comment already.

[atrol]

@dregad I didn't review / test. Just one disadvantage for now: Your server must have access to https://endoflife.date to run the check. This might not be allowed on a hardened server.

[dregad]

Thanks for the feedback.

Your server must have access to https://endoflife.date/ to run the check. This might not be allowed on a hardened server.

At the time I started coding this in October last year it was not yet available, but the endoflife.date team recently added a new API endpoint https://endoflife.date/docs/api/v1/#/Products that could be leveraged to download a selective dump of release data that we need to check, which we could bundle with our release tarballs.

I'll look into it.