Deprecated function for PHP 8.1 (line 11 autoload.cache.inc)

Problem/Motivation

After uploading Drupal 7 from PHP 7.2 to PHP 8.1, several errors appeared related to autoload:

Deprecated function: Return type of ArrayContainer::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::current() should either be compatible with Iterator::current(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::next() should either be compatible with Iterator::next(): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::key() should either be compatible with Iterator::key(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::valid() should either be compatible with Iterator::valid(): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::rewind() should either be compatible with Iterator::rewind(): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).
Deprecated function: Return type of ArrayContainer::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in require_once() (line 11 of /var/www/html/docroot/sites/all/modules/contrib/autoload/autoload.cache.inc).

Steps to reproduce

Test a D7 with autoloader and PHP 8.1

Proposed resolution

As the error message suggests; use [\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

Remaining tasks

User interface changes

API changes

Data model changes