Github actions cost

.github/workflows/deploy-site.yml

@@ -3,10 +3,18 @@ name: Deploy Website
 on:
   push:
     branches: [main]
+    paths:
+      - 'docs/**'
+      - 'mkdocs.yml'
+      - 'chapters/*/README.md'
 
 permissions:
   contents: write
 
+concurrency:
+  group: deploy-site
+  cancel-in-progress: true
+
 jobs:
   deploy:
     runs-on: ubuntu-latest
@@ -17,6 +25,7 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: "3.11"
+          cache: pip
 
       - name: Install dependencies
         run: pip install mkdocs-material mkdocs-minify-plugin

.github/workflows/validate-chapters.yml

@@ -14,20 +14,22 @@ on:
       - 'interactive/**'
       - 'templates/**'
 
+concurrency:
+  group: validate-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   validate:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        python-version: ["3.10", "3.11", "3.12"]
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up Python ${{ matrix.python-version }}
+      - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.11"
+          cache: pip
 
       - name: Install dependencies
         run: |