[FIX] assign correct YML version compatibility to PHP 7.0 - Moving changes to branch 2.x

[amarroni]

Per @Neodork comment I move all the changes to branch 2.x

[Neodork]

• There is an issue ticket which accompanies my PR: Bug: YML package no longer support PHP 7.0 by default causing switch to 7.0 to fail #542.
• I have followed the guidelines for contributing.
• I have checked that there aren't other open pull requests for the same issue ticket.
• I have formatted my code with the PSR-2 coding style before submitting my PR.

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I have read the contribution guidelines and am targeting the branch <YOUR_TARGET_BRANCH>:
Because this is a Bug Fix which is Backwards Compatible.

Changelog entry:
Short description of your work as explained by: Keep A Changelog.

• Fixed PECL YML package no longer supporting PHP 7.0 beyond version 2.0.4.

[Neodork]

Hey @amarroni! First of all thank you for your quick response I really appreciate that. This issue was blocking and it would feel unfair to me to take away your credits after you've provided us with a PR.

Your provided PR is all green! We can merge this and it will be added to the next release of valet-plus.