Patch `Performance/RedundantBlockCall` to teach it about Sorbet `sig`s

[sambostock]

We disable Performance/RedundantBlockCall because "[it] conflicts with Sorbet since we need to capture the block to type it."

There is precedent for RuboCop extensions patching cops defined somewhere else, and this seems like a reasonable thing to patch. If the method definition is prefixed with a sig, this cop should not complain about capturing the block argument, even if yield is used.

[sambostock]

Another option would be to teach the cop about Sorbet upstream in rubocop-performance, but that is likely to be rejected.