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.

scripts/build-ssl.sh

@@ -21,7 +21,7 @@ build_openssl_linux () {
     (
         cd "openssl-${OPENSSL_VERSION}/"
         ./config shared --prefix="${HOME}/opt" --openssldir="${HOME}/opt" -DPURIFY
-        make -j$(nproc) all
+        make -j$(nproc) build_sw
         make install_sw
     )
 }
@@ -31,7 +31,7 @@ build_openssl_osx () {
         cd "openssl-${OPENSSL_VERSION}/"
         ./Configure darwin64-x86_64-cc shared \
             --prefix="${HOME}/opt" --openssldir="${HOME}/opt" -DPURIFY
-        make depend all install_sw
+        make depend build_sw install_sw
     )
 }