Prepare 5.6.0 release

Author: MaxDesiatov

.github/workflows/manual-distribution.yml

@@ -59,6 +59,10 @@ jobs:
               export TARGETS_TO_DIST="ubuntu18.04_x86_64 ubuntu20.04_x86_64 macos_x86_64 macos_arm64"
               ./utils/webassembly/distribute-latest-toolchain.sh ${BRANCH:-swiftwasm-release/5.5} 5.5 "${{ github.event.inputs.toolchain_name }}"
             ;;
+            "5.6")
+              export TARGETS_TO_DIST="amazonlinux2_x86_64 ubuntu18.04_x86_64 ubuntu20.04_x86_64 ubuntu20.04_aarch64 macos_x86_64 macos_arm64"
+              ./utils/webassembly/distribute-latest-toolchain.sh ${BRANCH:-swiftwasm-release/5.6} 5.6 "${{ github.event.inputs.toolchain_name }}"
+            ;;
             *)
               echo "Unrecognised release channel: ${{ github.event.inputs.channel }}"
               exit 1