I think OpenSSL is useful for cross-testing (see #635) but I find the benchmark are annoying:

• They take very long.
• It's currently not possible to disable them without disabling the OpenSSL tests.
• Compilation of benchmark_verify is a special case in the build, see build: fix OpenSSL EC detection on macOS #735.

I think the benchmarks were useful in the early days of this library to demonstrate that it outperforms OpenSSL but this not necessary anymore.

Do people agree that we should remove them?