Then don't? In C you would just implement everything yourself, so go do that in Rust if you don't want dependencies.

In C I've seen more half-baked json implementations than I can count on my fingers because using dependencies is too cumbersome in that ecosystem and people just write it themselves but most of the time with more bugs.

If you care about not having any dependencies, then choosing dependencies that themselves don't have many dependencies should be going into the ones that you choose.

Direct and transitive dependencies are locked and hashed.