Add concurrency settings for workflow (#970)

.github/workflows/build_imaginary.yml

@@ -12,6 +12,8 @@ on:
         default: true
         description: Set to `false` to trigger _just_ a redeployment
 
+concurrency: ${{ github.workflow }}-${{ inputs.deploy-to }}
+
 jobs:
   build:
     name: Build

.github/workflows/ci_cd.yml

@@ -10,6 +10,13 @@ on:
       - published
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name == 'release' && 'release' || github.ref }}
+  # Don't continue building images for a PR if the PR is updated quickly
+  # For other workflows, allow them to complete and just block on them. This
+  # ensures deployments in particular to happen in series rather than parallel.
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   lint:
     name: Lint

.github/workflows/migration_safety_warning.yml

@@ -5,6 +5,11 @@ on:
     paths:
       - "**/migrations/**/*"
 
+concurrency:
+  # The concurrency group contains the workflow name and the branch name for pull requests.
+  group: ${{ github.workflow }}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 jobs:
   check-and-apply-labels:
     name: "Check and Apply Labels"

.github/workflows/push_docker_image.yml

@@ -9,6 +9,8 @@ on:
         description: Commit that the image is built from
         required: true
 
+concurrency: ${{ github.workflow }}-${{ inputs.image }}-${{ inputs.commit }}
+
 jobs:
   push:
     name: Publish requested Docker image