Disable default toolchain and update dockerfiles

.github/actions/build/action.yml

@@ -18,7 +18,7 @@ inputs:
   build_dockerfile:
     description: "build dockerfile path"
     required: true
-    default: ".maintain/docker/build.Dockerfile"
+    default: ".maintain/docker/ubuntu:20.04.Dockerfile"
   enable_cache:
     description: "enable cache"
     required: false

.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
         uses: docker/build-push-action@v4
         with:
           context: .
-          file: .maintain/docker/build.Dockerfile
+          file: .maintain/docker/ubuntu:20.04.Dockerfile
           tags: darwinia-network/build-tool:latest
 
       - name: Build testnets

.maintain/docker/build.Dockerfile → .maintain/docker/ubuntu:20.04.Dockerfile

@@ -1,20 +1,14 @@
 FROM ubuntu:20.04
 
-ARG RUST_TOOLCHAIN=nightly
-
-
 RUN apt-get update \
     && apt install --no-install-recommends -y \
-       ca-certificates curl git python3-pip \
-       clang make gcc g++ libssl-dev pkg-config protobuf-compiler \
+        ca-certificates curl git python3-pip \
+        clang make gcc g++ libssl-dev pkg-config protobuf-compiler \
     && pip3 install --upgrade pip \
     && pip3 install cmake --upgrade \
-    && curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y \
-    && . "/root/.cargo/env" \
-    && rustup default $RUST_TOOLCHAIN
+    && curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain none \
+    && . "/root/.cargo/env"
 
 ENV PATH="$PATH:/root/.cargo/bin"
 
 WORKDIR /build
-
-