Set the target for testing.

Having a .cargo/config.toml file is annoying if you want to run tests,
as it will attempt to compile the tests for the embedded target.

.github/workflows/ci_checks.yml

@@ -43,7 +43,7 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
-      - run: cargo test
+      - run: cargo test --target=x86_64-unknown-linux-gnu
   linting:
     name: Linting
     runs-on: ubuntu-latest