Deprecated: Implicitly nullable parameter $referenceTableName in Audit::addConstraint()

[sca1235]

Issue Description:

While using vcian/laravel-db-auditor, the following deprecation warning is thrown:

Deprecated: Vcian\LaravelDBAuditor\Traits\Audit::addConstraint(): Implicitly marking parameter $referenceTableName as nullable is deprecated, the explicit nullable type must be used instead in /vendor/vcian/laravel-db-auditor/src/Traits/Audit.php on line 92

This is due to a change in PHP where function parameters with a default value of null must now explicitly be marked as nullable.

File: vendor/vcian/laravel-db-auditor/src/Traits/Audit.php

Line: 92

Current Code:

public function addConstraint(
    string $table,
    string $field,
    string $constraint,
    string $referenceTableName = null,
    string $referenceField = null
): bool

Proposed Fix:

To resolve this deprecation, the $referenceTableName and $referenceField parameters in the addConstraint function should be explicitly declared as nullable by prefixing their type with a question mark (?).

Updated Code:

public function addConstraint(
    string $table,
    string $field,
    string $constraint,
    ?string $referenceTableName = null,
    ?string $referenceField = null
): bool

This change will make the code compliant with the latest PHP standards and remove the deprecation warning.