only build no_std aarch64 none on nightly

Author: domenukk

.github/workflows/main.yml

@@ -59,10 +59,13 @@ jobs:
       - name: Test `no_std` support
         run: cargo test --no-default-features --features=alloc,no_std_net
       - name: Build `url` crate for `aarch64-unknown-none` with `no_std`
-        run: >
+        if: |
+          matrix.os == 'ubuntu-latest' &&
+          matrix.rust == 'nightly'
+        run: |
           cd url
-          && cargo +nightly check -Zbuild-std=core,alloc --target aarch64-unknown-none -v --release --no-default-features --features=alloc,unstable
-          && cargo +nightly check -Zbuild-std=core,alloc --target aarch64-unknown-none -v --release --no-default-features --features=alloc,no_std_net
+          cargo +nightly check -Zbuild-std=core,alloc --target aarch64-unknown-none -v --release --no-default-features --features=alloc,unstable
+          cargo +nightly check -Zbuild-std=core,alloc --target aarch64-unknown-none -v --release --no-default-features --features=alloc,no_std_net
 
   WASM:
     runs-on: ubuntu-latest