Fix MSRV check.

Author: RazrFalcon

.github/workflows/main.yml

@@ -105,5 +105,6 @@ jobs:
     - name: Install toolchain
       uses: dtolnay/[email protected]
 
-    - name: Run tests
-      run: cargo test --all-features
+    # do not test, because dev-dependencies do not follow MSRV
+    - name: Build
+      run: cargo build --all-features