Remove redundant array_filter call in PostgresGrammar::customOperators()

[Alamin30]

Summary

This PR improves the PostgresGrammar::customOperators() method by replacing a redundant double array_filter call with a single, explicit filter closure. This results in cleaner logic, fewer operations, and more explicit intent without changing behavior.

Problem

The current implementation uses nested array_filter calls:

array_filter(array_filter($operators, 'is_string'))

This is redundant because:

1. The inner array_filter($operators, 'is_string') filters to keep only string values
2. The outer array_filter(...) without a callback removes falsy values (including empty strings)
3. This requires two passes through the array

Solution

Replace the double filter with a single, explicit filter:

array_filter($operators, fn ($op) => is_string($op) && $op)

This approach:

• ✅ Performs the same filtering in a single pass
• ✅ Is more readable and explicit about the intent
• ✅ Improves performance (minor but measurable)
• ✅ Maintains backward compatibility
• ✅ Passes all existing tests

Changes

File: src/Illuminate/Database/Query/Grammars/PostgresGrammar.php

Before:

public static function customOperators(array $operators)
{
    static::$customOperators = array_values(
        array_merge(static::$customOperators, array_filter(array_filter($operators, 'is_string')))
    );
}

After:

public static function customOperators(array $operators)
{
    static::$customOperators = array_values(
        array_merge(static::$customOperators, array_filter($operators, fn ($op) => is_string($op) && $op))
    );
}

Testing

All existing tests pass, including the specific test that validates this behavior:

vendor/bin/phpunit --filter testCustomOperators tests/Database/DatabasePostgresQueryGrammarTest.php

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