[11.x] Fix the RateLimiter issue when using dynamic keys

[MilesChou]

In Laravel v11.29.0, a new modification was introduced to the RateLimiter via PR #53177, which provides a fallback key when no unique key is specified. However, this mechanism can cause issues in scenarios where the key is determined dynamically using a closure.

For example, when implementing rate limiting based on dynamic userId values:

$rateLimiter->for('user_limiter', fn (string $userId) => [
    Limit::perSecond(3)->by($userId),
    Limit::perMinute(5)->by($userId),
]);

$userId1 = '123';
$userId2 = '456';

$limiterForUser1 = $rateLimiter->limiter('user_limiter')($userId1);
$limiterForUser2 = $rateLimiter->limiter('user_limiter')($userId2);

In version 11.29.0, the Limit::by($userId) method is ignored, and the fallback key is used instead, causing rate limiting records for different userId values to interfere with each other.

This fix ensures that if the original limit has a recorded key, it uses the original key as a prefix. For more details, please refer to the PR.

[gofish543]

@MilesChou Thank you for getting this PR in, was just about to submit one myself as a chunk of an application's unit tests are failing due to this change...

<?php

namespace App\RateLimiters;

use Illuminate\Cache\RateLimiting\Limit;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\RateLimiter;

class Web
{
    public static function register(): void
    {
        RateLimiter::for('web', function (Request $request) {
            $user = $request->user();
            $ip = $request->ip();

            return [
                Limit::perSecond(5)
                    ->by($user ? $user->id : $ip),

                Limit::perMinute(20)
                    ->by($user ? $user->id : $ip),

                Limit::perHour(80)
                    ->by($user ? $user->id : $ip),

                Limit::perDay(320)
                    ->by($user ? $user->id : $ip),
            ];
        });
    }
}

test('limited by user id', function () {
    $rateLimiter = RateLimiter::limiter('web');
    $user = User::factory()->make();
    $user->setUniqueIds();

    $request = Request::instance();
    $request->setUserResolver(fn () => $user);

    $limiters = $rateLimiter($request);

    dd(collect($limiters)->pluck('key'));
    expect($limiters)->toHaveCount(4);
    expect($limiters[0]->key)->toEqual($user->id);
});

Illuminate\Support\Collectio#2249
  #items: array:4 [
    0 => "attempts:5:decay:1"
    1 => "attempts:20:decay:60"
    2 => "attempts:80:decay:3600"
    3 => "attempts:320:decay:86400"
  ]
  #escapeWhenCastingToString: false
}

@timacdonald Any word on getting this merged?

[timacdonald]

Sorry about this one, folks.