This also adds new keys for SPHINCS+. The reason is that SPHINCS+
was updated to 3.1 in liboqs (open-quantum-safe/liboqs/pull/1420),
and old keys are incompatible with the new implementation.
Keys were generated using the oqs-provider for OpenSSL 3
openssl genpkey \
-provider default -provider oqsprovider \
-algorithm sphincsshake128fsimple \
-outform der \
-out bench_sphincs_fast_level1_key.der
And certs_test.h was updated using xxd
xxd -i -c 10 -u bench_sphincs_fast_level1_key.der
This was repeated for the 6 variants of SPHINCS+ that wolfSSL supports.