Add 5.6 to nightly-distribution.yml

Author: MaxDesiatov

.github/workflows/nightly-distribution.yml

@@ -20,6 +20,9 @@ jobs:
           - branch: "swiftwasm-release/5.5"
             channel: "5.5"
             targets: "ubuntu18.04_x86_64 ubuntu20.04_x86_64 macos_x86_64 macos_arm64"
+          - branch: "swiftwasm-release/5.6"
+            channel: "5.6"
+            targets: "amazonlinux2_x86_64 ubuntu18.04_x86_64 ubuntu20.04_x86_64 ubuntu20.04_aarch64 macos_x86_64 macos_arm64"
     steps:
       - uses: actions/checkout@v1
       - name: Setup keychain