contracts-bedrock: delete sherlock upgrade scripts

Deletes these old upgrade scripts that were used to
upgrade the contracts on goerli with the sherlock audit
fixes. These scripts are not general enough to be used
again, so there is no need to keep them around.

Removing them will help to speed up compile time.
`solc` takes awhile at this point to compile the
contracts repo so we should prune out code that is
not being used or will not be used in the future.

We should iterate on the design so that we can have generic
upgrade scripts in the future.