Ignore .ddev folder on composer builds

I created an MR, but the potential issue here is that Drupal’s packager provides a default .gitattributes file, so by adding this file to our module repository, the module maintainer assumes responsibility for keeping it in sync with the scaffold file from Drupal infra.

Perhaps the better solution would be to have Drupal infra to just exclude .ddev folders from all package builds.

Asked @drumm in Slack about this:

Would it make any sense to open an issue Drupal.org packaging to automatically exclude the .ddev folder from contrib package builds, so that maintainers do not need to add their own .gitattributes export-ignore rule?

his response:

The majority of requests about packaging are for it to do less. The .info.yml modifications can be annoying, but are necessary. So I don’t think I’d want to have it do more. I do think there is a place for an optional project template for new projects that includes the right LICENSE.txt , default .gitattributes and anything else mostly universal.

Since this is not a new project, it wouldn't really apply, and if such a project ever took off I guess we could add/update our .gitattributes to match a template.

Therefore I'm going to go ahead and merge this one. We need to continue to monitor the builds to confirm that the .ddev folder is actually getting removed, before marking this fixed.