Remove duplicate install_js_dependencies call causing CI failures

The install generator already handles JavaScript dependencies through the
shakapacker installer process. Our added call to install_js_dependencies
in add_js_dependencies was creating a duplicate installation process that
caused gem version conflicts during testing.

Root cause:
- bundle add shakapacker --strict adds "shakapacker = 8.2.0"
- react_on_rails.gemspec has "shakapacker >= 6.0"
- Bundler conflict: same gem with different version requirements

Fix: Remove the redundant install_js_dependencies call, keeping only the
method definition (moved to private section) for potential future use.

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

Co-Authored-By: Claude <[email protected]>

Author: ihabadham

lib/generators/react_on_rails/base_generator.rb

@@ -100,7 +100,6 @@ def add_js_dependencies
         add_react_dependencies
         add_css_dependencies
         add_dev_dependencies
-        install_js_dependencies
       end
 
       def update_gitignore_for_auto_registration