chore: 移除冗余的 GitHub 插件配置

由于已有 GitHub CLI 工具和其他插件支持，移除冗余的 github 官方插件配置以简化环境。

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: CodeCasterX

.claude/settings.json

@@ -66,7 +66,6 @@
     "commit-commands@claude-plugins-official": true,
     "context7@claude-plugins-official": true,
     "feature-dev@claude-plugins-official": true,
-    "github@claude-plugins-official": true,
     "jdtls-lsp@claude-plugins-official": true,
     "pr-review-toolkit@claude-plugins-official": true,
     "pyright-lsp@claude-plugins-official": true,