chore: fix typing of few nullable properties #1677

Job	Run time
Entrypoint low-PHP compat	10s
PHP 7.4 Fixer with lowest deps	59s
PHP 7.4 tests with lowest deps	3m 8s
PHP 8.0 Fixer	41s
PHP 8.0 tests	2m 56s
PHP 8.1 Fixer with Symfony ^6	49s
PHP 8.1 tests with Symfony ^6	3m 23s
PHP 8.2 Fixer	53s
PHP 8.2 tests	3m 36s
PHP 8.3 Fixer	45s
PHP 8.3 tests	3m 30s
PHP 8.3 Fixer with migration rules	1m 12s
PHP 8.3 tests with migration rules	3m 45s
PHP 8.3 Fixer with Symfony ^7	54s
PHP 8.3 tests with Symfony ^7	3m 47s
PHP 8.3 code coverage	4m 48s
PHP 8.3 mutation tests	26s
PHP 8.3 Fixer on Windows	1m 35s
PHP 8.3 tests on Windows	2m 24s
PHP 8.3 Fixer on macOS	1m 35s
PHP 8.3 tests on macOS	1m 48s
PHP 8.4 Fixer	43s
PHP 8.4 tests	3m 35s
Deployment checks	55s
	48m 17s

Provide feedback