cojson-simple-sync doesn't run in node20

[markmelville]

With node20 (v20.12.2), installing and running cojson-simple-sync (version 0.6.1, also tried 0.6.1-alpha.0) results in this error:

COJSON sync server listening on port 4200
file:///.../node_modules/cojson-simple-sync/dist/index.js:10
globalThis.crypto = webcrypto;
                  ^

TypeError: Cannot set property crypto of #<Object> which has only a getter
    at file:///.../node_modules/cojson-simple-sync/dist/index.js:10:19

I switched to node18, reinstalled, and it runs fine.