build: stop installing nightly for check

Author: anonrig

.github/workflows/ci.yml

@@ -29,8 +29,6 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
-      - run: rustup toolchain install nightly --profile minimal
-
       - uses: Swatinem/rust-cache@v2
         with:
           shared-key: ci