[11.x] Remove unreachable code in AssertableJsonString

[seriquynh]

This return $this statement is never touch because PHPUnit::fail() stands above it always throws an Exception .

[driesvints]

Can you change the return docblock to void as well?

[seriquynh]

@driesvints It's the assertMissingExact method and actually returns $this or fails.

<?php

public function assertMissingExact(array $data)
{
    // Domething something

    foreach (Arr::sortRecursive($data) as $key => $value) {
        $unexpected = $this->jsonSearchStrings($key, $value);

        if (! Str::contains($actual, $unexpected)) {
            return $this; // It returns $this here.
        }
    }

    // PHPUnit::fail()
}