doc: update README for 3.0.0 #734

Job	Run time
Symfony - PHP 8.2 - flags - mysqldump default-mysql-client	1m 40s
Symfony - PHP 7.4 - flags update --prefer-lowest - mysqldump	1m 27s
Symfony ^5.4 - PHP 7.4 - flags - mysqldump	1m 43s
Symfony ^5.4 - PHP 8.1 - flags - mysqldump	1m 34s
Symfony ^5.4 - PHP 8.1 - flags - mysqldump mariadb-client	1m 37s
Symfony ^6.4 - PHP 8.2 - flags - mysqldump	1m 41s
Symfony - PHP 8.2 - flags remove --dev --no-progress doctrine/phpcr-bundle doctrine/phpcr-odm - mysqldump	1m 36s
Symfony ^7.0 - PHP 8.2 - flags remove --dev --no-progress doctrine/phpcr-bundle doctrine/phpcr-odm - mysqldump	1m 37s
Symfony ^7.0 - PHP 8.3 - flags remove --dev --no-progress doctrine/phpcr-bundle doctrine/phpcr-odm - mysqldump	1m 35s
	14m 30s

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