sirenia and libsirenia: Depend on dev-rust/thiserror.

This adds a dependency on dev-rust/thiserror.

BUG=None
TEST=CQ passes

Change-Id: Ic10d09ff27cd6ca85dd464e1cc86e75478aad2ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2595852
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Nicole Anderson-Au <nvaa@google.com>
Commit-Queue: Allen Webb <allenwebb@google.com>
Tested-by: Allen Webb <allenwebb@google.com>
Auto-Submit: Allen Webb <allenwebb@google.com>
2 files changed