fix: `ConstantCaseFixer` - do not change namespace #9584

Job	Run time
PHP 7.4 Fixer with lowest deps	1m 46s
PHP 7.4 tests with lowest deps	2m 43s
PHP 8.0 Fixer	1m 7s
PHP 8.0 tests	3m 1s
PHP 8.1 Fixer with Symfony ^6	1m 16s
PHP 8.1 tests with Symfony ^6	2m 59s
PHP 8.2 Fixer	1m 11s
PHP 8.2 tests	2m 55s
PHP 8.3 Fixer	1m 37s
PHP 8.3 tests	3m 6s
PHP 8.3 Fixer with migration rules	2m 23s
PHP 8.3 tests with migration rules	4m 2s
PHP 8.3 Fixer with Symfony ^7	1m 34s
PHP 8.3 tests with Symfony ^7	3m 17s
PHP 8.3 code coverage	4m 23s
PHP 8.3 mutation tests	41s
PHP 8.3 Fixer on Windows	2m 28s
PHP 8.3 tests on Windows	2m 16s
PHP 8.3 Fixer on macOS	2m 5s
PHP 8.3 tests on macOS	2m 17s
PHP 8.4 Fixer	1m 29s
PHP 8.4 tests	3m 40s
Deployment checks (ubuntu-20.04, 8.2)	1m 1s
	53m 17s

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