Remove *_stub crates from workspace

These were erronously added by https://crrev.com/c/3530503

BUG=b:228384796
TEST=None

Change-Id: Id13fd1568e897025cc917c7af4f0bd711185bf1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3575715
Reviewed-by: Junichi Uekawa <uekawa@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dennis Kempin <denniskempin@google.com>
diff --git a/Cargo.toml b/Cargo.toml
index 92583b6..eed7e2d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -64,7 +64,6 @@
     "kernel_loader",
     "kvm",
     "kvm_sys",
-    "libcras_stub",
     "linux_input_sys",
     "media/libvda",
     "net_sys",
@@ -75,7 +74,6 @@
     "resources",
     "rutabaga_gfx",
     "serde_keyvalue",
-    "system_api_stub",
     "tpm2",
     "tpm2-sys",
     "usb_sys",