minor #4069 DX: Add dev-tools directory to gitattributes as export-ignore (alexmanno)
minor #4069 DX: Add dev-tools directory to gitattributes as export-ignore (alexmanno)

This PR was squashed before being merged into the 2.12 branch (closes #4069).

Discussion
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DX: Add dev-tools directory to gitattributes as export-ignore

Commits
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7f2e87a3 DX: Add dev-tools directory to gitattributes as export-ignore

gharlan/PHP-CS-Fixer,keradus/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,keradus/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer