Remove scrutinizer

[vjik]

Q	A
Is bugfix?	❌
New feature?	❌
Breaks BC?	❌

[what-the-diff]

PR Summary

• Update to ignored files
  The .gitattributes file was modified, and the /.scrutinizer.yml file was removed from its list of ignored files.

• Deletion of outdated configuration file
  The old configuration file .scrutinizer.yml was deleted.

• Update to project documentation
  The README.md file, which acts as the project's documentation, had some updates. The Scrutinizer Code Quality and Code Coverage badges, which indicated old measurement tools of our code health, were removed. Instead, we're now using the Code Coverage badge from Codecov, a tool for understanding how thoroughly our tests cover the codebase.