chore(ci): move the actions to their node24 releases

The runner warns that the node20 action runtime is deprecated. Every
action in the workflow was on it:

  checkout             v4 -> v7
  setup-go             v5 -> v7
  setup-node           v4 -> v7
  upload-pages-artifact v3 -> v5
  deploy-pages         v4 -> v5

The two Pages actions move together because the artifact format is
shared between them.

None of the inputs this workflow passes changed across those majors —
the releases are ESM migrations and the runtime bump. `node-version: 24`
was already the Node the build runs on; this is about the runtime the
actions themselves execute in.

.github/workflows/deploy-pages.yml

@@ -26,9 +26,9 @@ jobs:
       # explicitly rather than relying on the default.
       CGO_ENABLED: '0'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@v7
         with:
           go-version: '1.26'
           cache-dependency-path: |
@@ -37,7 +37,7 @@ jobs:
             assembler/go.sum
 
       # web/ is the only npm project in the repository; the other stages are Go.
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v7
         with:
           node-version: '24'
           cache: 'npm'
@@ -91,7 +91,7 @@ jobs:
       - name: Build site
         run: go -C assembler run ./cmd/assemble
 
-      - uses: actions/upload-pages-artifact@v3
+      - uses: actions/upload-pages-artifact@v5
         with:
           path: _site
 
@@ -108,4 +108,4 @@ jobs:
       url: ${{ steps.deployment.outputs.page_url }}
     steps:
       - id: deployment
-        uses: actions/deploy-pages@v4
+        uses: actions/deploy-pages@v5