Checking no debugger on JRuby

fixes tests for JRuby
Remove unused variable

This method is not using the block variable directly since it is calling
yield
Typo fix
Merge pull request #13102 from akshay-vishnoi/typo

Typo fix
Fix URL to robots.txt documentation
Merge pull request #13097 from arunagw/jruby-test-fixes

Skipping debugger inclusion test if JRuby
Merge pull request #13104 from christophemaximin/fix_robots_txt_link

Fix URL to robots.txt documentation [ci skip]
Improve Module#delegate documentation to tell that delegate don't work with private or protected methods. [ci skip]
Merge pull request #13092 from laurocaetano/improve_documentation_for_delegate

Improve Module#delegate documentation.