ci: install setuptools to prevent Python distutils errors during dependency installation

.github/actions/setup-bun/action.yml

@@ -31,6 +31,10 @@ runs:
         bun-version-file: ${{ !steps.bun-url.outputs.url && 'package.json' || '' }}
         bun-download-url: ${{ steps.bun-url.outputs.url }}
 
+    - name: Install setuptools for distutils compatibility
+      run: python3 -m pip install setuptools || pip install setuptools || true
+      shell: bash
+
     - name: Install dependencies
       run: bun install
       shell: bash