[PHP] Error sending request via GuzzleHttp

What are you generating using Kiota, clients or plugins?

API Client/SDK

In what context or format are you using Kiota?

Nuget tool

Client library/SDK language

PHP

Describe the bug

Unable to upload large attachment. In the file Microsoft\Kiota\Abstractions\RequestHeaders, the array_keys function is used, which returns keys as numbers. If a large file is sent that is split into smaller parts, the size of the part is sent. However, the size is a number, so the key is cast to a number. This is a PHP feature, where a key that looks like a number is cast to a number. See the issue: https://github.com/microsoftgraph/msgraph-sdk-php/issues/1794

An error is returned in the getAll method: Since guzzlehttp/psr7 2.11: Passing int to GuzzleHttp\Psr7\Request::__construct() is deprecated; guzzlehttp/psr7 3.0 requires string|string[].

Instead of array_keys, you must use foreach.

Expected behavior

See description

How to reproduce

See description

Open API description file

No response

Kiota Version

2.0.2

Latest Kiota version known to work for scenario above?(Not required)

No response

Known Workarounds

No response

Configuration

No response

Debug output

</details>


### Other information

_No response_

Start in Microsoft\Kiota\Abstractions\RequestHeaders and inspect the getAll method, especially its handling of numeric-looking header values. Reproduce the large multipart upload scenario described in the issue and verify that the resulting request no longer passes an integer to GuzzleHttp\Psr7\Request.