Make phpdoc type case-sensitive

[kkmuffme]

https://psalm.dev/r/84fbd22c02

Related #8089
Inspired by #8465 (comment)

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/84fbd22c02

<?php

use dateTime;

/**
 * @param dAteTime $arg
 * @return void
 */
function a( $arg ) {
	/** @var daTeTime $arg */
    echo $arg->format('Y-m-d H:i:s');
}

Psalm output (using commit afe85fa):

ERROR: UnnecessaryVarAnnotation - 10:11 - The @var dateTime annotation for $arg is unnecessary

[orklah]

fixed :)