Run rustup self-update as a separated step

.github/workflows/bors.yml

@@ -72,6 +72,9 @@ jobs:
         with:
           github_token: "${{ secrets.GITHUB_TOKEN }}"
       - uses: actions/checkout@v2
+      - name: Self-update rustup
+        run: rustup self update
+        shell: bash
       - name: Setup Rust toolchain
         run: TARGET=${{ matrix.target }} sh ./ci/install-rust.sh
         shell: bash

.github/workflows/main.yml

@@ -64,6 +64,9 @@ jobs:
           - target: i686-pc-windows-msvc
     steps:
       - uses: actions/checkout@v2
+      - name: Self-update rustup
+        run: rustup self update
+        shell: bash
       - name: Setup Rust toolchain
         run: TARGET=${{ matrix.target }} sh ./ci/install-rust.sh
         shell: bash

ci/install-rust.sh

@@ -12,7 +12,6 @@ else
 fi
 if [ "$OS" = "windows" ]; then
   : "${TARGET?The TARGET environment variable must be set.}"
-  rustup self update
   rustup set profile minimal
   rustup update --force $toolchain-"$TARGET"
   rustup default $toolchain-"$TARGET"