Issue #3224421 by ankithashetty, daffie, andypost, longwave, alexpott, xjm: [PHP 8.1] Add a shim to Guzzle 6 for PHP 8.1 compatibility

Issue #3232691 by alexpott, longwave: Refactor \Drupal\Core\Ajax\AjaxHelperTrait to not cause deprecations in PHP 8.1

Issue #3217322 by effulgentsia, xjm, Gábor Hojtsy: Update dependencies except PHPUnit to latest releases as of June 3, 2021

Issue #3213295 by effulgentsia, tedbow, longwave, Spokje, xjm, catch: Update Symfony 5 components to 5.3-rc1

Issue #3211805 by xjm, Kristen Pol, longwave: Update composer/composer dev dependency in metapackages to 2.0.13

Issue #3209459 by longwave, catch, andypost: Switch to friends of behat MinkBrowserKitDriver for PHP 8 and Symfony 5 compatibility

Issue #2844452 by Eduardo Morales Alberti, longwave, andypost, Wongjn, sanjayk, geek-merlin, ayushmishra206, Hardik_Patel_12, alexpott, catch, DamienMcKenna, dww, anruether, dawehner, jrockowitz: Export configuration YAML strings as multiline

Revert "Issue #2844452 by Eduardo Morales Alberti, longwave, andypost, sanjayk, geek-merlin, ayushmishra206, Hardik_Patel_12, alexpott, DamienMcKenna, dww, anruether, dawehner, jrockowitz: Export configuration YAML strings as multiline"

This reverts commit 677700aa.

Issue #2844452 by Eduardo Morales Alberti, longwave, andypost, sanjayk, geek-merlin, ayushmishra206, Hardik_Patel_12, alexpott, DamienMcKenna, dww, anruether, dawehner, jrockowitz: Export configuration YAML strings as multiline

Issue #3198594 by catch, longwave, nikitagupta, alexpott, andypost: Forward compatibility layer for InputBag

Issue #3192842 by gabesullice, xjm, phenaproxima, lhockley, thalles: Make our README more welcoming by converting it into an "entrypoint" into the Drupal ecosystem

SA-CORE-2021-001 by larowlan, stephenacrossri, siliconmeadow, mcdruid, xjm, vijaycs85, mlhess, greggles

Issue #3096781 by longwave, xjm, catch, Eric_A, mikelutz: symfony/mime and symfony/var-dumper versions are on 5.1.7 (not an LTS) and therefore have gaps in security coverage relative to Drupal minors

Issue #3098281 by greg.1.anderson, alexpott, heddn, Mile23, xjm, jungle, longwave: Ensure that 'composer update' evaluates dependencies using the correct PHP version

Issue #3180207 by andypost, alexpott, Gábor Hojtsy, Mixologic, xjm: Update laminas-diactoros, laminas-escaper and laminas-feed for PHP 8 compatibility

Issue #3176655 by alexpott, jungle, longwave, ayushmishra206, Gábor Hojtsy, andypost: Deprecate GoutteDriver use in core and use Behat\Mink\Driver\BrowserKitDriver directly instead

Issue #3179875 by greg.1.anderson, Mixologic: Path repositories need to be listed first for Composer 2