fix(ci): Remove gradle cache from gh-pages workflow

docToolchain uses its own gradle, no gradle files in repo to cache

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: rdmueller

.github/workflows/gh-pages.yml

@@ -31,7 +31,6 @@ jobs:
         with:
           distribution: 'temurin'
           java-version: '17'
-          cache: 'gradle'
 
       - name: Setup dtcw
         run: chmod +x dtcw