The release of Go 1.21.6 includes the new boring crypto when compiling
with FIPS enabled. See https://go.dev/doc/devel/release#go1.21.0 and
https://github.com/golang/go/issues/64717.
This new version of boring crypto allows the use of TLS v1.3 for the
first time, so we changed the Pinniped code to use TLS v1.3 where
appropriate when compiled with the FIPS compiler. It also changed the
allowed TLS v1.2 ciphers, so we updated those as well.
After this commit, the project must be compiled by at least Go v1.21.6
when compiling in fips mode. The hack/Dockerfile_fips was already
updated to use that version of Go in a previous commit.
Co-authored-by: Benjamin A. Petersen <ben@benjaminapetersen.me>