Release 0.39.0 (#226)

Sync with `polkadot-v1.8.0`

Author: smiasojed

.gitlab-ci.yml

@@ -90,8 +90,8 @@ build-mac:
   before_script:
     - unset CARGO_TARGET_DIR
   script:
-    - rustup component add rust-src
-    - rustup target add wasm32-unknown-unknown
+    - rustup component add rust-src rustfmt
+    - rustup target add wasm32-unknown-unknown aarch64-apple-darwin
     - time cargo build --release --target aarch64-apple-darwin
     - rustup target add x86_64-apple-darwin
     - time cargo build --release --target x86_64-apple-darwin