chore: Fix CI msrv workflow (#1176)

.github/workflows/CI.yml

@@ -1,8 +1,5 @@
 name: CI
 
-env:
-  MSRV: "1.60"
-
 on:
   push:
     branches:
@@ -49,22 +46,23 @@ jobs:
   #   - uses: EmbarkStudios/cargo-deny-action@v1
 
   msrv:
-    name: Check MSRV (${{ env.MSRV }})
+    name: Check MSRV
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v1
-      - name: Install Rust (${{ env.MSRV }})
+      - name: Install Rust
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: ${{ env.MSRV }}
+          toolchain: "1.60"
           override: true
-      - name: Check
-        uses: actions-rs/cargo@v1
+      - name: Install Protoc
+        uses: arduino/setup-protoc@v1
         with:
-          command: check
-          args: --all --all-targets --all-features
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Check
+        run: cargo check --all --all-targets --all-features
 
   test:
     runs-on: ${{ matrix.os }}