update actions/checkout from v3 to v4 (#199)

Update release.yml

Author: PixelPil0t1

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
         package: [halo2curves]
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - uses: actions-rs/toolchain@v1
         with:
             profile: minimal