Don't install musl-tools

It seems like this isn't needed to compile for any of the `*-musl` targets because they don't need
to compile any C code.

.github/workflows/ci.yml

@@ -127,9 +127,6 @@ jobs:
         run: |
           git config --global user.email "[email protected]"
           git config --global user.name "J. Doe"
-      - name: Install musl-tools on Linux
-        run: sudo apt-get update --yes && sudo apt-get install --yes musl-tools
-        if: contains(matrix.platform.name, 'musl')
       - name: Build binary
         uses: houseabsolute/actions-rust-cross@v0
         with: