Update serde_json, lru and crossbeam-channel.

This upgrades serde_json, lru, crossbeam-channel and there dependencies
to pick-up RDEPEND and fix a crash that showed up after
dev-lang/rust-1.51.0 landed.

BUG=chromium:1182669,b:18689421
TEST=./build_packages --board=${BOARD}

Cq-Depend: chrome-internal:3815845, chrome-internal:3815807
Change-Id: I32a0464f95257291d4daa9be4b1758662c407757
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2880502
Tested-by: Allen Webb <allenwebb@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Allen Webb <allenwebb@google.com>
diff --git a/dev-rust/rustc-std-workspace-alloc/rustc-std-workspace-alloc-1.0.0.ebuild b/dev-rust/rustc-std-workspace-alloc/rustc-std-workspace-alloc-1.0.0.ebuild
new file mode 100644
index 0000000..e5b72b0
--- /dev/null
+++ b/dev-rust/rustc-std-workspace-alloc/rustc-std-workspace-alloc-1.0.0.ebuild
@@ -0,0 +1,17 @@
+# Copyright 2021 The Chromium OS Authors. All rights reserved.
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI="7"
+
+CROS_RUST_EMPTY_CRATE=1
+
+inherit cros-rust
+
+DESCRIPTION="Empty crate"
+HOMEPAGE=""
+
+LICENSE="BSD-Google"
+SLOT="${PV}/${PR}"
+KEYWORDS="*"
+
+# This file was automatically generated by cargo2ebuild.py