php8.1 issues

Thank you so much for your work developing and keeping alive post-smtp. It is a life-saver.

We are still using php8.0, so this isn’t an issue yet, but are looking to move to php8.1. We ran across these errors:

Deprecated: Return type of FS_Key_Value_Storage::offsetExists($k) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 309

Deprecated: Return type of FS_Key_Value_Storage::offsetGet($k) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 317

Deprecated: Return type of FS_Key_Value_Storage::offsetSet($k, $v) 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 /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 301

Deprecated: Return type of FS_Key_Value_Storage::offsetUnset($k) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 313

Deprecated: Return type of FS_Key_Value_Storage::current() should either be compatible with Iterator::current(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 328

Deprecated: Return type of FS_Key_Value_Storage::next() should either be compatible with Iterator::next(): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 339

Deprecated: Return type of FS_Key_Value_Storage::key() should either be compatible with Iterator::key(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 350

Deprecated: Return type of FS_Key_Value_Storage::valid() should either be compatible with Iterator::valid(): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 362

Deprecated: Return type of FS_Key_Value_Storage::rewind() should either be compatible with Iterator::rewind(): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 375

Deprecated: Return type of FS_Key_Value_Storage::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/dev.adst.org/wp-content/plugins/post-smtp/freemius/includes/managers/class-fs-key-value-storage.php on line 389

Just wanted to report them. Thank you again.