Move Drush to the development section of the makefile for Aegir compatibility

[colans]

Currently, it's not possible to install a Y site on Aegir because it requires a site-local Drush. See Aegir 3 is incompatible with Drush 9+ for details.

Given that Drush isn't generally required for Production sites, the simplest and best-practice workaround is to move it from require to require-dev so that it's still available in development environments, but not in Aegir deployments (which always assume Production).

Original Issue, this PR is going to fix: NA; this MR is self-contained.

Steps for review

1. Get access to an Aegir instance by setting it up on a real VM or by using https://gitlab.com/aegir/aegir-dev-vm.
2. Create a new Platform (Aegir-speak for a Drupal codebase) using https://github.com/ymcatwincities/openy-project.
3. Create a site using the Open Y distro on that Platform.

If everything is green, it succeeded. If you get errors as described in Aegir 3 is incompatible with Drush 9+, then it failed.

General checks

• [ ] All coding styles are fulfilled and there are no any issues reported by CodeSniffer. See Code of Conduct.
• [ ] Try to use Conventional commit messages accordingly to the standard https://www.conventionalcommits.org/en/v1.0.0/#specification
• [ ] Documentation has been updated according to PR changes.
• [ ] Steps for review have been provided according to PR changes.
  
• [ ] Make sure you've provided all necessary hook_update_N to support upgrade path.
• [ ] Make sure your git email is associated with account on drupal.org, otherwise you won't get commits there.
  
• [ ] If you would like to get credits on drupal.org, check documentation.

[gundevel]

Can one of the admins verify this patch? Use "o+k to test" or ''t+est this please" for manual build execution.

[sarah-halby]

@podarok can you please review? @shelleygoetz please open a ticket in Jira.

[podarok]

There is a chance CI will be broken, I'll verify overnight @sarah-halby

Thank you @colans

[gundevel]

Can one of the admins verify this patch? Use "o+k to test" or ''t+est this please" for manual build execution.

[colans]

Thanks! That was fast. I created a d.o issue for credit purposes @ https://www.drupal.org/project/openy/issues/3253330

[gundevel]

Can one of the admins verify this patch? Use "o+k to test" or ''t+est this please" for manual build execution.

[podarok]

Thanks! That was fast. I created a d.o issue for credit purposes @ https://www.drupal.org/project/openy/issues/3253330

Fixed on drupal.org. Thank you

[gundevel]

Can one of the admins verify this patch? Use "o+k to test" or ''t+est this please" for manual build execution.

[shelleygoetz]

@sarah-halby created: (https://openy.atlassian.net/browse/MAINTAIN-222)

[gundevel]

Can one of the admins verify this patch? Use "o+k to test" or ''t+est this please" for manual build execution.

[podarok]

[skip ci]

[gundevel]

Can one of the admins verify this patch? Use "o+k to test" or ''t+est this please" for manual build execution.