Update rust-toolchain file for new rustup

Rustup since version 1.23.0 supports more detailed specification.

.github/workflows/build.yml

@@ -42,9 +42,6 @@ jobs:
         rustc -Vv
         cargo -Vv
 
-    - name: "Install Rustup Components"
-      run: rustup component add rust-src llvm-tools-preview
-
     - name: "Install build tools"
       run: cargo install cargo-make cargo-binutils
 
@@ -133,7 +130,6 @@ jobs:
     timeout-minutes: 10
     steps:
     - uses: actions/checkout@v1
-    - run: rustup toolchain install nightly --profile minimal --component clippy
-    - run: rustup component add rust-src llvm-tools-preview
+    - run: rustup toolchain install nightly
     - run: cargo install cargo-make
     - run: env CLIPPY_FEATURES=${{ matrix.features }} cargo make clippy

rust-toolchain

@@ -1 +1,4 @@
-nightly
+[toolchain]
+channel = "nightly"
+components = ["clippy", "llvm-tools-preview", "rust-src", "rustfmt"]
+targets = ["aarch64-unknown-none-softfloat"]