mu-plugins: Reset stats cache on upload

We’ve pushed a fix to properly clear an internal stats cache for uploaded files. This was causing an incorrect filesize value to be returned after an upload (if done within the same request).

wp> $file = wp_upload_bits( 'hello.txt', 'world' )['file'];
int(5)
wp> filesize( $file );
int(5) <= this would previously return 0

The fix was pushed in our mu-plugins repo here:

https://github.com/Automattic/vip-go-mu-plugins/pull/1741

#mu-plugins