CI: Set up concurrency groups for CI

This should set things up to automatically cancel a run once a new one
is pushed to a PR.

.github/workflows/code-analysis.yml

@@ -1,5 +1,9 @@
 name: "Code Analysis"
 
+concurrency:
+  group: ${{ github.workflow}}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 on:
   push:
     branches: [main]

.github/workflows/docs-conda.yml

@@ -5,6 +5,10 @@ on:
   pull_request:
     branches: [ main ]
 
+concurrency:
+  group: ${{ github.workflow}}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 jobs:
   #
   # Build our docs on macOS and Windows on Python 3.8 and 3.7, respectively.

.github/workflows/docs.yml

@@ -15,6 +15,10 @@ on:
 permissions:
   contents: write
 
+concurrency:
+  group: ${{ github.workflow}}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 jobs:
   #
   # Build our docs on Linux against multiple Pythons

.github/workflows/linting.yml

@@ -4,6 +4,10 @@ on:
     branches: [main]
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow}}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 jobs:
   flake8:
     name: Flake8

.github/workflows/tests-conda.yml

@@ -7,6 +7,10 @@ on:
   pull_request:
     branches: [ main ]
 
+concurrency:
+  group: ${{ github.workflow}}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 jobs:
   #
   # Run all tests on Conda on both Windows and macOS

.github/workflows/tests-pypi.yml

@@ -7,6 +7,10 @@ on:
   pull_request:
     branches: [ main ]
 
+concurrency:
+  group: ${{ github.workflow}}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 jobs:
   #
   # Run all tests on Linux using standard PyPI packages, including minimum requirements