⬆️ Upgrade Ubuntu version for docs workflow (#5971)

.github/workflows/build-docs.yml

@@ -7,7 +7,7 @@ on:
     types: [opened, synchronize]
 jobs:
   build-docs:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - name: Dump GitHub context
         env:
@@ -17,7 +17,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: "3.7"
+          python-version: "3.11"
       - uses: actions/cache@v3
         id: cache
         with: