2.7.0: Support Symfony 7, Drop support for outdated versions of Symfony, PHP and PHPUnit

⚠️ Despite our best efforts, the MySQL backup may be broken.

See:

• #244

What's Changed

• caveats.md: add path of file by @alexislefebvre in #222
• use a github note on installation doc by @alexislefebvre in #223
• remove Style CI by @alexislefebvre in #226
• README: set branch in badge of GH actions by @alexislefebvre in #227
• feat: drop support for php < 7.4 by @Chris53897 in #229
• chore: allow monolog/monolog v3 for require-dev by @Chris53897 in #232
• chore: fix warning for phpunit 10 (static data providers) by @Chris53897 in #231
• chore: remove phpunit 8 by @Chris53897 in #233
• feat: remove unnecessary (duplicated) interfaces by @Chris53897 in #230
• chore: migrate and update php-cs-fixer 2 => 3 by @Chris53897 in #234
• Replace uses of deprecated Connection::query() method by @mbabker in #240
• chore: require symfony 6.3 by @alexislefebvre in #242
• chore: test symfony 5.4 on PHP 8.1 by @alexislefebvre in #243
• chore: skip testLoadFixturesCheckReferences by @alexislefebvre in #247
• feat: drop support for symfony 4 by @Chris53897 in #246
• feat: allow symfony 7 by @Chris53897 in #248

Full Changelog: 2.6.0...2.7.0