Revert "rust-bootstrap: update to 1.47.0"

This reverts commit 15fffdf9565e697e8c2561e455824c131d3f6ac7.

Reason for revert: bootstrap should only go with a Rust uprev

Original change's description:
> rust-bootstrap: update to 1.47.0
>
> BUG=None
> TEST=emerge rust-bootstrap
>
> Change-Id: I762d97f9ec2dd42f19d07de7d2c314f2512f62b9
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2555621
> Reviewed-by: Tiancong Wang <tcwang@google.com>
> Commit-Queue: Tiancong Wang <tcwang@google.com>
> Tested-by: Tiancong Wang <tcwang@google.com>

Bug: None
Change-Id: Ibcdcaac3e117e21d20f94dfb4212ee7e07e1fc9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2558713
Reviewed-by: Tiancong Wang <tcwang@google.com>
Commit-Queue: Tiancong Wang <tcwang@google.com>
Tested-by: Tiancong Wang <tcwang@google.com>
9 files changed