[UPMERGE] 3.0 -> 3.1 (#284)

This PR has been generated automatically.
For more details see
[upmerge_pr.yaml](/Sylius/MolliePlugin/blob/1.0/.github/workflows/upmerge_pr.yaml).

**Remember!** The upmerge should always be merged with using `Merge pull
request` button.

In case of conflicts, please resolve them manually with usign the
following commands:
```
git fetch upstream
gh pr checkout <this-pr-number>
git merge upstream/3.1 -m "Resolve conflicts between 3.0 and 3.1"
```

If you use other name for the upstream remote, please replace `upstream`
with the name of your remote pointing to the `Sylius/MolliePlugin`
repository.

Once the conflicts are resolved, please run `git merge --continue` and
push the changes to this PR.

Author: NoResponseMate

assets/shop/js/mollie/app.js

@@ -365,12 +365,7 @@ document.addEventListener('DOMContentLoaded', function () {
     }
 
     function initializeCreditCartFields(selectedValue) {
-        const environment = mollieData.getAttribute('data-environment');
-        let testmode = true;
-
-        if (environment === 1) {
-            testmode = false;
-        }
+        const testmode = '' === mollieData.getAttribute('data-environment');
 
         const mollie = Mollie(mollieData.getAttribute('data-profile_id'), {
             locale: mollieData.getAttribute('data-locale'),

src/Repository/MollieSubscriptionRepository.php

@@ -19,7 +19,7 @@
 use Sylius\Component\Core\Model\PaymentInterface;
 use Sylius\MolliePlugin\Entity\MollieSubscriptionInterface;
 
-final class MollieSubscriptionRepository extends EntityRepository implements MollieSubscriptionRepositoryInterface
+class MollieSubscriptionRepository extends EntityRepository implements MollieSubscriptionRepositoryInterface
 {
     public function findOneByOrderId(int $orderId): ?MollieSubscriptionInterface
     {