Avoid installing rustc-dev in the rustfmt CI job

.github/workflows/main.yml

@@ -12,9 +12,11 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
-    - name: Install rustfmt
+    - name: Avoid installing rustc-dev
       run: |
-        rustup component add rustfmt
+        sed -i 's/components.*/components = ["rustfmt"]/' rust-toolchain
+        echo 'profile = "minimal"' >> rust-toolchain
+        rustfmt -v
 
     - name: Rustfmt
       run: |