Im on Wordpress version 5.9.1. I created a barebones theme to see if my theme was the issue, but these errors persisted.
Deprecated: Return type of Gravity_Forms\Gravity_Forms\External_API\GF_API_Response::jsonSerialize() should either be compatible with JsonSerializable::jsonSerialize(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/wp-content/plugins/gravityforms/includes/external-api/class-gf-api-response.php on line 179
Deprecated: version_compare(): Passing null to parameter #1 ($version1) of type string is deprecated in /var/www/html/wp-content/plugins/gravityforms/includes/addon/class-gf-addon.php on line 5818
Deprecated: Return type of GF_Field::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/wp-content/plugins/gravityforms/includes/fields/class-gf-field.php on line 93
Deprecated: Return type of GF_Field::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/wp-content/plugins/gravityforms/includes/fields/class-gf-field.php on line 99
Deprecated: Return type of GF_Field::offsetSet($offset, $data) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/wp-content/plugins/gravityforms/includes/fields/class-gf-field.php on line 108
Deprecated: Return type of GF_Field::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/wp-content/plugins/gravityforms/includes/fields/class-gf-field.php on line 117
Deprecated: Gravity_Forms\Gravity_Forms\License\GF_License_API_Response implements the Serializable interface, which is deprecated. Implement __serialize() and __unserialize() instead (or in addition, if support for old PHP versions is necessary) in /var/www/html/wp-content/plugins/gravityforms/includes/license/class-gf-license-api-response.php on line 17
Cannot modify header information - headers already sent by (output started at /var/www/html/wp-content/plugins/gravityforms/includes/external-api/class-gf-api-response.php:15)