Remove and replace php-symfony-polyfill-* dependencies

As discussed in #911832, the polyfilled dependencies can safely be replaced with PHP extensions. For non-builtin extensions (apcu, intl, mbstring), we need to manually add the dependency for now to avoid inheriting the version constraint against the polyfill.

All of the packages in the Build-Depends already have their native extensions being installed. The hardcoded autoloader entries in d/*.autoload.php.tpl were also removed.

Finally, this also takes care of the circular dependency between php-symfony-intl and php-symfony-polyfill-intl-icu by removing the dependency upon the polyfill.

Closes: #821138

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I prepared this on the buster branch since that's what debcheckout gave me - is that the correct branch?

added 2 commits

• 0edc7bf4 - Remove and replace php-symfony-polyfill-* dependencies
• 6a5bfe99 - Update changelog for 3.4.20+dfsg-2 release

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changed title from Drop Build-Depends on php-symfony-polyfill-* to {+Remove and replace php-symfony-polyfill- dependencies+}*

changed the description

@taffit I'd appreciate it if you could give this a quick look over before I upload it tomorrow, since there's a decent amount of changes.

If you want me to have a look, just wait a few days: a new upstream release (3.4.21) is due soon, I’ll then take care of the upload.

Changes cherry-picked and in their way with 3.4.21+dfsg-1 just uploaded, thanks.

closed

mentioned in issue phpmyadmin-team/phpmyadmin#22 (closed)

mentioned in merge request phpmyadmin-team/phpmyadmin!14 (closed)

mentioned in commit 28bf1808