update libjsonnet to v0.20.0

[rben01]

No description provided.

[rben01]

Struggling to get this to compile. We need to include rapid_yaml, but putting the following in build.rs doesn't work.

for f in ["ryml_std.hpp", "ryml.hpp"] {
    c.file(dir.join("third_party/rapidyaml/rapidyaml/src").join(f));
}

Update: I think I've got it working: cargo build successfully builds this crate.