fix: move sync-wiki.yml secrets to env block to resolve SonarCloud S7636

Move github.actor, secrets.GITHUB_TOKEN, and github.repository from
inline run block string interpolation to step-level env: block.
References via env vars prevent secret expansion in workflow logs.

Resolves the remaining S7636 hotspot in sync-wiki.yml.

Closes #106

.github/workflows/sync-wiki.yml

@@ -50,4 +50,8 @@ jobs:
           git commit -m "Sync wiki from source repository"
 
           # Push changes
-          git push https://${{ github.actor }}:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.wiki.git
+          git push https://${WIKI_ACTOR}:${WIKI_TOKEN}@github.com/${WIKI_REPO}.wiki.git
+        env:
+          WIKI_ACTOR: ${{ github.actor }}
+          WIKI_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          WIKI_REPO: ${{ github.repository }}