Update Google benchmark dependency (#3917)
Update Google benchmark dependency (#3917)

1.5.4 is unable to build with clang 13. Upgrading to 1.5.6 should
address that issue.

We still can't update FreeBSD as 1.5.3 continues to be the last
version that builds on it.
dipinhora/ponyc,sgebbie/ponyc,sgebbie/ponyc,dipinhora/ponyc,jemc/ponyc,sgebbie/ponyc,dipinhora/ponyc,jemc/ponyc,ponylang/ponyc,ponylang/ponyc,ponylang/ponyc,sgebbie/ponyc,jemc/ponyc,sgebbie/ponyc