Fix double spend via delegatecall

[k06a]

Similar issue: OpenZeppelin/openzeppelin-contracts#2852

[marktoda]

Thanks for submitting! We considered this during development but decided against explicitly supporting delegatecalls to permit2 -- we think that permit2 works best when theres a single instance to get maximal network effects. If other teams have improvements or special needs, then a fully separate deployment is best. Happy to discuss further but closing for now

cc @snreynolds

[k06a]

I understand that intention to delegatecall this code is wrong, but it was an attempt to protect developers/users even from misuse, especially if this protection would costs almost zero gas.