[TASK] Raise PHPStan to level 7 #4238

Job	Run time
PHP Lint (8.2)	12s
PHP Lint (7.3)	33s
PHP Lint (7.2)	22s
PHP Lint (8.5)	13s
PHP Lint (8.0)	40s
PHP Lint (8.1)	41s
PHP Lint (8.3)	18s
PHP Lint (7.4)	28s
PHP Lint (8.4)	17s
Static Analysis (php:codesniffer, 8.3)	28s
Static Analysis (php:rector, 8.3)	35s
Unit tests (8.0)	21s
Unit tests (8.1)	30s
Unit tests (7.4)	23s
Static Analysis (composer:normalize, 8.3)	19s
Static Analysis (php:fixer, 8.3)	27s
Unit tests (8.2)	17s
Static Analysis (php:stan, 8.3)	28s
Unit tests (8.5)	18s
Unit tests (7.2)	37s
Unit tests (8.4)	17s
Unit tests (7.3)	30s
Unit tests (8.3)	13s
	9m 27s

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