ci: set configure-pages enablement:false to fix Pages deploy failure

The pages-deploy job was failing with:
  Create Pages site failed. Error: Resource not accessible by integration

`actions/configure-pages@v5` with `enablement: true` calls the GitHub API to
create/enable the Pages site, which requires admin-level permissions the
GITHUB_TOKEN doesn't have. Changing to `enablement: false` makes the step only
configure the deployment environment URL without touching the site API.

GitHub Pages must be enabled once in the repository settings
(Settings → Pages → Source: GitHub Actions) for the deploy to publish a URL,
but the job will no longer fail on every run.

Co-authored-by: fiddlerwoaroof <808745+fiddlerwoaroof@users.noreply.github.com>

.github/workflows/ci.yml

@@ -165,12 +165,14 @@ jobs:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}
     steps:
-      # `enablement: true` asks the API to turn Pages on with source =
-      # GitHub Actions. It succeeds only if the repository allows the workflow
-      # token to do so; if it does not, this step is where the run fails and
-      # the fix is the repository setting, not this file (improvise-3gy).
+      # `enablement: false` (the default) configures the environment URL
+      # without attempting to create or modify the Pages site via the API.
+      # GitHub Pages must be enabled once in the repository settings
+      # (Settings → Pages → Source: GitHub Actions) before this job will
+      # produce a live URL. Using `enablement: true` fails when the workflow
+      # token lacks admin permission to create the site (improvise-3gy).
       - uses: actions/configure-pages@v5
         with:
-          enablement: true
+          enablement: false
       - id: deployment
         uses: actions/deploy-pages@v4