The intent was to check the valid until date on my websites' TLS certificates.
I got this far before I realized that WASM (GOARCH=wasm GOOS=js) does not
support network calls.
Even WASI (GOARCH=wasm GOOS=wasip1) can only support a subset,
and even then only with a third-party library.
I guess I'll have to use node after all...
Leaving this here in case significant advancements are made in the near future.