Remove unecessary core dev version replacement in locale project info

Problem/Motivation

In #3590050: Deprecate and replace locale_status related functions (currently only in the 11.x backport), we change how the installer downloads and detects po files during the import-phase. As part of that, we have to update lots of tests from hardcoded 8.0.0 versions to the current version based on Drupal::VERSION.

One concern was the magic -dev replacement that's happening in \Drupal\locale\LocaleProjectRepository::buildProjects() and is also duplicated into the installer in install_check_translations():

       elseif (preg_match("/^(\d+\.\d+\.).*$/", $data['info']['version'], $matches)) {
          // Example match: 8.0.0-dev => 8.0.x (Drupal core)
          $data['info']['version'] = $matches[1] . 'x';
        }

But that's not how we do dev versions anymore, we don't do that on patch release. It is not so long ago, it was in #3445211: Composer tests fail because of invalid Drupal version as that is not actually a semantically correct version. It's now for example 11.4-dev or 12.0-dev.

drupal.org handles this now and it supports basically any suffix, including for contrib, these all work:

https://ftp.drupal.org/files/translations/all/drupal/drupal-12.0-dev.de.po
https://ftp.drupal.org/files/translations/all/drupal/drupal-11.4-dev.de.po
https://ftp.drupal.org/files/translations/all/drupal/drupal-8.0.0-dev.de.po
https://ftp.drupal.org/files/translations/all/drupal/drupal-8.0.0-banana...

It also works for contrib if there's an actual release

works: https://ftp.drupal.org/files/translations/all/address/address-2.0.x-dev....
does not work: https://ftp.drupal.org/files/translations/all/address/address-2.x-dev.de.po

Steps to reproduce

Proposed resolution

Removed the regex in those two places, adjust tests.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet