Change Details

Core composer.json already specifies 4.5: https://git.wikimedia.org/blob/mediawiki%2Fcore.git/85d6495c9adc8e8eb3f914ff600cfd89e71d16f1/composer.json#L30 . It seems like it could be changed in https://git.wikimedia.org/blob/integration%2Fphpunit.git/8402beb78f2b4c2bcc4e12195d82ca182cfe0dc3/composer.json pretty easily, but not sure if there are hidden issues (I would expect a few tests would need to be updated, but I'm wondering if there's anything bigger).