[ci] Ensure i18n up to date

.github/workflows/build-book.yml

@@ -21,22 +21,12 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: "3.9"
+          cache: pip
 
       - name: Upgrade pip
         run: |
           # install pip=>20.1 to use "pip cache dir"
           python3 -m pip install --upgrade pip
-      - name: Get pip cache dir
-        id: pip-cache
-        run: echo "::set-output name=dir::$(pip cache dir)"
-
-      - name: Cache dependencies
-        uses: actions/cache@v4
-        with:
-          path: ${{ steps.pip-cache.outputs.dir }}
-          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
-          restore-keys: |
-            ${{ runner.os }}-pip-
 
       - name: Install dependencies
         run: python3 -m pip install nox

.github/workflows/i18n.yaml

@@ -0,0 +1,39 @@
+name: Check Internationalization
+# Ensure that the .po files are up to date with any changes to the guide text
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  update-i18n:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+          cache: pip
+
+      - name: Install Nox
+        run: python3 -m pip install nox
+
+      - name: Update .po files
+        run: nox -s update-translations
+
+      - name: Test for uncommitted changes
+        run: |
+          if [ -z "$(git status --porcelain)" ];
+          then
+            echo "No changes detected, translations are up to date!" >> $GITHUB_STEP_SUMMARY
+            exit 0
+          else
+            echo "Changes to .po files detected, please run `nox -s update-translations` to reflect changes to source text" >> $GITHUB_STEP_SUMMARY
+            echo "$(git status)"
+            echo "$(git diff)"
+            exit 1
+          fi