Add concurrency flag to each job to resolve race conditions

.github/workflows/deploy-existing-release.yml

@@ -3,6 +3,11 @@ name: Deploy Existing Release
 on:
   workflow_dispatch:
 
+# Ensure only one instance of either this or the publish workflow is running at a time
+# This ensures that we don't put production into an inconsistent state
+concurrency:
+  group: 'prod-deployment'
+
 jobs:
   deploy:
     runs-on: ubuntu-latest

.github/workflows/main.yml

@@ -4,6 +4,11 @@ on:
   push:
     branches: ["main"]
 
+# Ensure only one instance of the workflow is running at a time
+# This helps with race conditions when upserting releases
+concurrency:
+  group: 'main'
+
 env:
   REGISTRY: ghcr.io
   IMAGE_NAME: ${{ github.repository }}

.github/workflows/publish-new-release.yml

@@ -3,6 +3,11 @@ name: Publish New Release
 on:
   workflow_dispatch:
 
+# Ensure only one instance of either this or the deploy workflow is running at a time
+# This ensures that we don't put production into an inconsistent state
+concurrency:
+  group: 'prod-deployment'
+
 jobs:
   deploy:
     runs-on: ubuntu-latest