Fix failing RSpec test after process manager docs update

Updated test expectation to match the new Foreman documentation link.

In commit 6cc93c7, we updated lib/react_on_rails/dev/process_manager.rb
to link to Foreman's official wiki instead of our outdated foreman-issues.md.
The test was still expecting the old link pattern.

Change:
- Old expectation: /foreman-issues\.md/
- New expectation: /Don't-Bundle-Foreman/

This matches the new error message which now points to:
https://github.com/ddollar/foreman/wiki/Don't-Bundle-Foreman

Fixes the failing spec:
ReactOnRails::Dev::ProcessManager.show_process_manager_installation_help
displays helpful error message with installation instructions

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

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

Author: ihabadham

spec/react_on_rails/dev/process_manager_spec.rb

@@ -234,7 +234,7 @@
       expect { described_class.send(:show_process_manager_installation_help) }
         .to output(/DO NOT add foreman to your Gemfile/).to_stderr
       expect { described_class.send(:show_process_manager_installation_help) }
-        .to output(/foreman-issues\.md/).to_stderr
+        .to output(/Don't-Bundle-Foreman/).to_stderr
     end
   end
 end