[3.x] Revert "chore: remove backup"

[alexislefebvre]

This reverts commit e11fb1d and

• [3.x] chore: remove backup #289

[alexislefebvre]

I had to use some weird tricks to fix the tests, this feature may be broken.

Like in this old PRs:

• fix: testLoadFixturesCheckReferences #244
• [WIP] PHPUnit: set executionOrder as random and enable resolveDependencies #8

---

To try this:

composer require --dev liip/test-fixtures-bundle:^3.1.0-alpha1

Please report issues or improvements after upgrading to this version.

[alexislefebvre]

A new alpha release has been published, please try it in your projects:

composer require --dev liip/test-fixtures-bundle:^3.1.0-alpha2

[jrjohnson]

I saw you opened a PR in ilios/ilios, but just to report both alpha1 and alpha2 look solid and run exactly as fast as 2.9.0. Looking great, thanks for rolling this back!