Auto merge of #109880 - ehuss:fix-macos-installer-rust-docs, r=Mark-Simulacrum

Fix macOS and Windows installers when rust-docs is not available.

This fixes the macOS `.pkg` and Windows `.msi` installers to work when rust-docs is not available. If the rust-docs component is not built, then the installer would fail. This adds the rust-docs component to the filtering mechanism so that the rust-docs line of the distribution definition aren't included.

I tested installing and uninstalling both with and without the rust-docs component available.

This happens on the aarch64-apple-darwin distribution provided by rust-lang since we currently disable the rust-docs component due to long build times. An alternate solution would be to just enable the rust-docs component on aarch64-apple-darwin since there are faster build systems.

Fixes #109877

Author: bors