docs: Improve the description for the clear cache option #31692

Job	Run time
Composer Validate	26s
Run with Space in Directory	22s
Help and Version	21s
Preload php-parser Order	19s
PHPStan	1m 27s
Compatible PHPStan versions	24s
Active Classes	25s
Check before/after test fixture on no-changes	21s
Finalize classes	22s
PHP Linter	31s
Check fixture classes are different to nodes	21s
Commented Code	26s
Detect composer dependency issues	20s
Check no "*.php" files in rules Fixture directory	24s
	6m 29s

Provide feedback