CI: ssl: do not needlessly build the OpenSSL docs

1/4 of the OpenSSL build time is spent building the docs, let's just
build the software and not the doc, by replacing the "all" target
with "build_sw". With this my build time drops from 1'28 to 1'09.

Nothing was done for the other libs, as it's unknown whether they
provide specific build targets.
1 file changed