Fix deprecated method usage

[johnnynotsolucky]

• Updates CLI to remove usage of deprecated method since Symfony 7.4
• Adds support for Symfony 8

Before, running ./bref with Symfony 7.4|8 installed would result in

./bref bref-cli -> main
PHP Fatal error:  Uncaught ErrorException: Since symfony/console 7.4: The "Symfony\Component\Console\Application::add()" method is deprecated and will be removed in Symfony 8.0, use "Symfony\Component\Console\Application::addCommand()" instead. in bref-cli/vendor/symfony/deprecation-contracts/function.php:25
Stack trace:
#0 [internal function]: Bref\Cli\Application->{closure:Bref\Cli\Application::turnWarningsIntoExceptions():85}(16384, 'Since symfony/c...', 'bref-cli/vendor/symfony/deprecation-contracts/function.php', 25)
#1 bref-cli/vendor/symfony/deprecation-contracts/function.php(25): trigger_error('Since symfony/c...', 16384)
#2 bref-cli/vendor/symfony/console/Application.php(558): trigger_deprecation('symfony/console', '7.4', 'The "%s()" meth...', 'Symfony\\Compone...', 'Symfony\\Compone...')
#3 bref-cli/src/Application.php(23): Symfony\Component\Console\Application->add(Object(Bref\Cli\Commands\Login))
#4 bref-cli/bref(14): Bref\Cli\Application->__construct()
#5 {main}
  thrown in bref-cli/vendor/symfony/deprecation-contracts/function.php on line 25

Fatal error: Uncaught ErrorException: Since symfony/console 7.4: The "Symfony\Component\Console\Application::add()" method is deprecated and will be removed in Symfony 8.0, use "Symfony\Component\Console\Application::addCommand()" instead. in bref-cli/vendor/symfony/deprecation-contracts/function.php:25
Stack trace:
#0 [internal function]: Bref\Cli\Application->{closure:Bref\Cli\Application::turnWarningsIntoExceptions():85}(16384, 'Since symfony/c...', 'bref-cli/vendor/symfony/deprecation-contracts/function.php', 25)
#1 bref-cli/vendor/symfony/deprecation-contracts/function.php(25): trigger_error('Since symfony/c...', 16384)
#2 bref-cli/vendor/symfony/console/Application.php(558): trigger_deprecation('symfony/console', '7.4', 'The "%s()" meth...', 'Symfony\\Compone...', 'Symfony\\Compone...')
#3 bref-cli/src/Application.php(23): Symfony\Component\Console\Application->add(Object(Bref\Cli\Commands\Login))
#4 bref-cli/bref(14): Bref\Cli\Application->__construct()
#5 {main}
  thrown in bref-cli/vendor/symfony/deprecation-contracts/function.php on line 25

After this change, the CLI works as expected.

[mnapoli]

Thank you so much!