refactor: update CI pipeline

Using now rustup show instead of the dedicated action-rs/toolchain
github action. This allows using the .toml extension. Thanks
@atifaziz for pointing out
actions-rs/toolchain#126 (comment)

.devcontainer/Dockerfile

@@ -35,7 +35,7 @@ RUN set -x && curl -sSL https://dot.net/v1/dotnet-install.sh | \
 # prompt to rebuild the container nor the Docker build cache to be invalidated.
 # Make sure to rebuild the container to ensure a fresh install of the new Rust
 # version also works.
-COPY ../rust-toolchain .
+COPY ../rust-toolchain.toml .
 
 # NB: we have to install also any components we need for our specific toolchain
 # version.

.github/workflows/e2e-ci.yml

@@ -15,7 +15,7 @@ on:
       - ".github/workflows/e2e.yaml"
       - 'Cargo.lock'
       - 'Cargo.toml'
-      - 'rust-toolchain'
+      - 'rust-toolchain.toml'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -37,7 +37,7 @@ jobs:
           sudo apt-get install cmake protobuf-compiler libprotobuf-dev
 
       - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
+        run: rustup show
 
       - name: Cache Dependencies
         uses: Swatinem/rust-cache@v1

.github/workflows/lt-ci.yml

@@ -16,7 +16,7 @@ on:
       - '.github/workflows/lt-ci.yml'
       - 'Cargo.lock'
       - 'Cargo.toml'
-      - 'rust-toolchain'
+      - 'rust-toolchain.toml'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -41,7 +41,7 @@ jobs:
       - uses: actions/checkout@v2
 
       - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
+        run: rustup show
 
       - name: Cache Dependencies
         uses: Swatinem/rust-cache@v1

.github/workflows/rust-ci.yml

@@ -18,7 +18,7 @@ on:
       - '.github/workflows/rust-ci.yml'
       - 'Cargo.lock'
       - 'Cargo.toml'
-      - 'rust-toolchain'
+      - 'rust-toolchain.toml'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -65,7 +65,7 @@ jobs:
       - name: Install protobuf-compiler
         run: sudo apt-get install -y protobuf-compiler
       - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
+        run: rustup show
       - name: Cache Dependencies
         uses: Swatinem/rust-cache@v1
       - name: Run cargo-tarpaulin

examples/applications/Dockerfile.base

@@ -45,7 +45,7 @@ ENV OPENSSL_DIR /musl
 
 WORKDIR /sdv
 
-COPY ./rust-toolchain .
+COPY ./rust-toolchain.toml .
 
 RUN rustup target add x86_64-unknown-linux-musl