Use PACKAGE_DEPLOY_KEY PAT for plotstyle publish workflow

The built-in Actions token was rejected by the Gitea package registry
(401 reqPackageAccess); a PAT with write:package scope is required.

.gitea/workflows/publish-plotstyle.yml

@@ -7,7 +7,6 @@ on:
 
 permissions:
   contents: read
-  packages: write
 
 jobs:
   publish:
@@ -34,6 +33,6 @@ jobs:
 
       - name: Publish to Gitea package registry
         env:
-          UV_PUBLISH_USERNAME: ${{ github.actor }}
+          UV_PUBLISH_USERNAME: lars
-          UV_PUBLISH_PASSWORD: ${{ secrets.GITHUB_TOKEN }}
+          UV_PUBLISH_PASSWORD: ${{ secrets.PACKAGE_DEPLOY_KEY }}
         run: uv publish --publish-url "${{ github.server_url }}/api/packages/${{ github.repository_owner }}/pypi" dist/*