Implicitly marking parameter $feed as nullable is deprecated

Problem/Motivation

Deprecated: Drupal\feeds_http_auth_fetcher\Feeds\Fetcher\Form\HttpAuthFetcherFeedForm::buildConfigurationForm(): Implicitly marking parameter $feed as nullable is deprecated, the explicit nullable type must be used instead in /var/www/html/backend/web/modules/contrib/feeds_http_auth_fetcher/src/Feeds/Fetcher/Form/HttpAuthFetcherFeedForm.php on line 26

Deprecated: Drupal\feeds_http_auth_fetcher\Feeds\Fetcher\Form\HttpAuthFetcherFeedForm::submitConfigurationForm(): Implicitly marking parameter $feed as nullable is deprecated, the explicit nullable type must be used instead in /var/www/html/backend/web/modules/contrib/feeds_http_auth_fetcher/src/Feeds/Fetcher/Form/HttpAuthFetcherFeedForm.php on line 59

Steps to reproduce

visit feeds edit form

Proposed resolution

fix types with "?" operator

Remaining tasks

Review merge request.

User interface changes

none

API changes

none

Data model changes

none