Move the workflows onto Node 24 action majors

CI warned that actions/checkout@v4 and actions/setup-python@v5 target
Node 20 and were being forced onto Node 24 (build-cv: .github#2).

Checked each major's published action.yml to find where the runtime
actually changes: checkout v5 and setup-python v6 are the first majors on
node24. Bumped to those rather than to the current v7s, since the smaller
jump clears the warning with less to go wrong. Both releases describe the
change as node24-only with no API break, needing runner v2.327.1 or
newer, which ubuntu-latest already provides.

Applied to all three workflows and parsed each one as YAML. Validation,
the page build, ruff, and the suite (348 passed, 12 skipped) are all
unchanged, and no generated file moved.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QQUWxAFYESZCZe3DLyy1eB

Author: jeremymanning

.github/workflows/build-content.yml

@@ -34,12 +34,12 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: true
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.11'
           cache: 'pip'

.github/workflows/build-cv.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: true
 
@@ -57,7 +57,7 @@ jobs:
           fc-list | grep -i "JetBrains Mono" || (echo "JetBrains Mono not registered" && exit 1)
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.11'
           cache: 'pip'

.github/workflows/test-llm-api.yml

@@ -27,10 +27,10 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.11'