Remove downgrade process

[samsonasik]

coding-standard seems only should be installable via ecs, so this PR remove the downgrade process.

[samsonasik]

@TomasVotruba ready for review, next steps needed:

• remove .72 suffix tags from packagist https://packagist.org/packages/symplify/coding-standard
• tag it
• add config in ecs composer.json

"minimum-stability": "dev",
"prefer-stable": true

so coding-standard will be installable from there.

• Re-tag easy-coding-standard.

[TomasVotruba]

I've removed the tags 👍

[samsonasik]

@TomasVotruba thank you, it works now 🎉 https://github.com/rectorphp/getrector.org/pull/982