📝 update - Add string datatype in increment and decrement method

[hasan-4]

framework/src/Illuminate/Database/Query/Builder.php

Line 3072 in 3d1ead4

* @param float|int $amount

framework/src/Illuminate/Database/Query/Builder.php

Line 3095 in 3d1ead4

* @param float|int $amount

Summary: in database, for decimal datatype add string datatype also

ref:
11.1.3 Fixed-Point Types (Exact Value) - DECIMAL, NUMERIC
12.25.2 DECIMAL Data Type Characteristics

//* @param  float|int|string  $amount 

Thank you