BlobKey, MirrorService and Sidekiq 8 are incompatible

# Bug report for Cloudinary Ruby SDK

## Describe the bug in a sentence or two.
When using the Cloudinary ActiveStorage service in a mirror with S3 and Sidekiq 8 as a job queue, I am getting errors of the form

> Job arguments to ActiveStorage::MirrorJob must be native JSON types, but "1xfiunhqeexf8h3pkdxucnby5eou" is a ActiveStorage::BlobKey

## Issue Type (Can be multiple)
- [ ] Build - Cannot install or import the SDK
- [ ] Performance - Performance issues
- [X] Behaviour - Functions are not working as expected (such as generate URL)
- [ ] Documentation - Inconsistency between the docs and behaviour
- [ ] Other (Specify)

## Steps to reproduce
- Use Sidekiq 8 with strict_args enabled (default)
- Define an S3 service and a Cloudinary Service in storage.yml
- Define a mirror as
```
mirror:
service: Mirror
primary: amazon
mirrors:
- cloudinary
```
- Attempt to upload a file
- ActiveStorage will attempt to enqueue ActiveStorage::MirrorJob which takes `key` as an arg. But because the Cloudinary gem is [redefining](https://github.com/cloudinary/cloudinary_gem/blob/master/lib/active_storage/service/cloudinary_service.rb#L11) the key as a `BlobKey` we get the above error from Sidekiq because BlobKey is not a native JSON type.

## Error screenshots or Stack Trace (if applicable)
lib/active_storage/service/mirror_service.rb:55

A minimal repro can be achieved with the following:

```
> s = ActiveStorage::Service::MirrorService.new(primary: nil, mirrors: [])
=> #
> k = ActiveStorage::BlobKey.new(key: "test")
=> "test"
> s.mirror_later(k, checksum: nil)
INFO 2025-05-15T14:47:39.511Z pid=955 tid=25v: Sidekiq 8.0.3 connecting to Redis with options {size: 10, pool_name: "internal", url: "redis://redis:6379/0"}
Failed enqueuing ActiveStorage::MirrorJob to Sidekiq(default): ArgumentError (Job arguments to ActiveStorage::MirrorJob must be native JSON types, but "test" is a ActiveStorage::BlobKey.
See https://github.com/sidekiq/sidekiq/wiki/Best-Practices
To disable this error, add `Sidekiq.strict_args!(false)` to your initializer.
```

This monkey patch to ActiveStorage can address the issue, but I dont know whether rails would want this in their core code when the expect the key to be a string anyway

```
module ActiveStorage
class Service::MirrorService < Service
def mirror_later(key, checksum:) # :nodoc:
ActiveStorage::MirrorJob.perform_later key.to_s, checksum: checksum
end
end
end
```

## Operating System
- [X] Linux
- [ ] Windows
- [ ] macOS
- [ ] All

## Environment and Libraries (fill in the version numbers)
- Cloudinary Ruby SDK version - 2.3.0
- Ruby Version - 3.4.3
- Rails Version - 7.2.2.1
- Other Libraries - ActiveStorage 7.2.2.1