Upgrade test application and drop support for PHP 7.4 and PHP 8.0

[loevgaard]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 36.36364% with 14 lines in your changes are missing coverage. Please review.

Project coverage is 41.47%. Comparing base (d4128a6) to head (e336b6d).

❗ Current head e336b6d differs from pull request most recent head 5964f90. Consider uploading reports for the commit 5964f90 to get more accurate results

Files	Patch %	Lines
src/EmailManager/GiftCardEmailManager.php	0.00%	2 Missing ⚠️
src/Fixture/Factory/GiftCardExampleFactory.php	0.00%	2 Missing ⚠️
src/Form/Type/GiftCardConfigurationType.php	0.00%	2 Missing ⚠️
...rc/Controller/Action/DownloadGiftCardPdfAction.php	0.00%	1 Missing ⚠️
src/Controller/Action/GiftCardBalanceAction.php	0.00%	1 Missing ⚠️
src/Doctrine/ORM/GiftCardRepository.php	0.00%	1 Missing ⚠️
src/Doctrine/ORM/OrderRepositoryTrait.php	0.00%	1 Missing ⚠️
src/EventSubscriber/GiftCardDeletionSubscriber.php	0.00%	1 Missing ⚠️
src/Exception/ChannelMismatchException.php	0.00%	1 Missing ⚠️
.../DataTransformer/GiftCardToCodeDataTransformer.php	0.00%	1 Missing ⚠️
... and 1 more

Additional details and impacted files

@@             Coverage Diff              @@
##             0.12.x     #264      +/-   ##
============================================
+ Coverage     41.30%   41.47%   +0.16%     
+ Complexity      597      594       -3     
============================================
  Files           108      107       -1     
  Lines          2116     2105      -11     
============================================
- Hits            874      873       -1     
+ Misses         1242     1232      -10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.