Run CI formatting checks for payjoin-ffi

Author: arminsabouri

.github/workflows/rust.yml

@@ -37,6 +37,19 @@ jobs:
       - run: rustup component add rustfmt --toolchain nightly-x86_64-unknown-linux-gnu
       - name: "Run formatting check"
         run: cargo fmt --all -- --check
+  
+  Format-FFI:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Install nightly toolchain"
+        uses: dtolnay/rust-toolchain@nightly
+      - name: "Use cache"
+        uses: Swatinem/rust-cache@v2
+      - run: rustup component add rustfmt --toolchain nightly-x86_64-unknown-linux-gnu
+      - name: "Run formatting check"
+        run: cd payjoin-ffi && cargo fmt --all -- --check
 
   Lint:
     runs-on: ubuntu-latest