Have rustdoc return its output directory instead of zip default.

[UebelAndre]

This is a breaking change for direct consumers of the rust_doc targets but fortunately the fix would be to simply consume the .zip target with the same name. The benefit to this change though is zips are not created by default which saves time.

[UebelAndre]

@scentini @krasimirgg would either of you be able to find out what's going on with the windows environment here? My changes here shouldn't impact these examples at all.
https://buildkite.com/bazel/rules-rust-rustlang/builds/8297#0186f03d-d1c4-4205-a79d-73fce2fce071

[scentini]

Sorry for the delay @UebelAndre , I've been quite swamped with other work recently. I'll try to take a look at the failure tomorrow.

[scentini]

I tried to reproduce today, but I couldn't get past some crate_universe error:

Error: Unused annotations were provided. Please remove them: [CrateId { name: "wepoll-ffi", version: "*" }]

@UebelAndre do you have some pointers here?
I guess I could figure out where the annotation comes from and remove it, but I probably shouldn't be getting a failure where CI passed.
This is what I ran locally (from the examples/crate_universe directory):

bazel --output_user_root=C:/b --windows_enable_symlinks build --enable_runfiles --nolegacy_external_runfiles --config=rustfmt --config=clippy -- //...

I also reran your CI and currently it's the Zig task that's failing (I guess we could disable that one for now as it wasn't fixed for a few days now?). I will keep looking into the Windows flake though, I noticed quite a few similar failures recently.