Fix PHP 8.4 deprecation warnings

[TomA-R]

What

Fixes deprecation warnings on PHP 8.4 - see https://php.watch/versions/8.4/implicitly-marking-parameter-type-nullable-deprecated

For example:

Deprecated: PhpcsChanged\shouldIgnorePath(): Implicitly marking parameter $patternOption as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/Cli.php on line 454
Deprecated: PhpcsChanged\LintMessages::fromLintMessages(): Implicitly marking parameter $fileName as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/LintMessages.php on line 36
Deprecated: PhpcsChanged\PhpcsMessages::fromPhpcsJson(): Implicitly marking parameter $forcedFileName as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/PhpcsMessages.php on line 14
Deprecated: PhpcsChanged\PhpcsMessages::fromArrays(): Implicitly marking parameter $fileName as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/PhpcsMessages.php on line 18
Deprecated: PhpcsChanged\PhpcsMessagesHelpers::fromPhpcsJson(): Implicitly marking parameter $forcedFileName as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/PhpcsMessagesHelpers.php on line 11
Deprecated: PhpcsChanged\PhpcsMessagesHelpers::fromArrays(): Implicitly marking parameter $fileName as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/PhpcsMessagesHelpers.php on line 46
Deprecated: PhpcsChanged\UnixShell::executeCommand(): Implicitly marking parameter $return_val as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/UnixShell.php on line 97
Deprecated: PhpcsChanged\CacheManager::__construct(): Implicitly marking parameter $debug as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/PhpcsChanged/CacheManager.php on line 48
Deprecated: PhpcsChangedTests\SvnFixture::getSvnInfo(): Implicitly marking parameter $lastChangedRevision as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/tests/helpers/SvnFixture.php on line 47
Deprecated: PhpcsChangedTests\TestShell::executeCommand(): Implicitly marking parameter $return_val as nullable is deprecated, the explicit nullable type must be used instead in phpcs-changed/tests/helpers/TestShell.php on line 88

Testing

[sirbrillig]

Oh! Great work. I knew these warnings were coming.