coco_keyprovider: abondon shadow dependency

shadow is actually not used in the project.

Signed-off-by: Xynnn007 <xynnn@linux.alibaba.com>

Author: Xynnn007

Cargo.lock

@@ -28,7 +28,6 @@ tonic.workspace = true
 uuid = { workspace = true, features = ["fast-rng", "v4"] }
 
 [build-dependencies]
-shadow-rs = "1.0.1"
 tonic-build.workspace = true
 
 [dev-dependencies]

attestation-agent/coco_keyprovider/Cargo.toml

@@ -3,12 +3,9 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-use shadow_rs::{BuildPattern, ShadowBuilder};
+use std::io;
 
-fn main() -> shadow_rs::SdResult<()> {
+fn main() -> Result<(), io::Error> {
     tonic_build::compile_protos("../protos/keyprovider.proto")?;
-    ShadowBuilder::builder()
-        .build_pattern(BuildPattern::RealTime)
-        .build()?;
     Ok(())
 }