Build/Test Tools: Exclude the .cache directory from PHPCS scans.

This avoids a fatal out-of-memory error when running `composer run lint` checks.

Props Soean.
Fixes #65649.

git-svn-id: https://develop.svn.wordpress.org/trunk@62766 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

phpcs.xml.dist

@@ -46,6 +46,7 @@
 	<exclude-pattern>/gutenberg/*</exclude-pattern>
 
 	<!-- Directories and third party library exclusions. -->
+	<exclude-pattern>/.cache/*</exclude-pattern>
 	<exclude-pattern>/node_modules/*</exclude-pattern>
 	<exclude-pattern>/vendor/*</exclude-pattern>