Return value of SyncCommand::execute() must be of the type int

Update CHANGELOG.md

Merge branch 'phpstan-1.0' into main

Add upgrade guide & update changelog

Update PHPStan to ^0.12.65

Update Rector to ^0.11

Add support for latest Rector dev

Replace deprecated rector/rector-prefixed with rector/rector

Fix hook_event_dispatcher Rector rule set

Fix references to Rector set lists