set explicit elixir version

Author: the-mikedavis

.github/workflows/peer-discovery-aws.yaml

@@ -51,7 +51,7 @@ jobs:
       uses: erlef/[email protected]
       with:
         otp-version: ${{ env.OTP_VERSION }}
-        elixir-version: latest
+        elixir-version: "1.17"
     - name: SETUP ecs-cli
       if: steps.authorized.outputs.authorized == 'true'
       env: