New S3 Configuration breaks prior S3 configuration and is missing uploadPartSize

Describe your Issue

I've used the S3 integration before "manually" via configs.s3.config.php, now the helm chart upgrade (v5.4.0) fails because it's already defined

Logs and Errors

Helm upgrade failed: error while running post render on files: map[string]interface {}(nil): yaml: unmarshal errors:
line 168: mapping key "s3.config.php" already defined at line 23

Describe your Environment

• Kubernetes distribution: k8s

• Helm Version (or App that manages helm):

• Helm Chart Version: 5.4.0

• values.yaml:

configs:
        s3.config.php: |-
          <?php
          $CONFIG = array (
            'objectstore' => array(
              'class' => '\\OC\\Files\\ObjectStore\\S3',
              'arguments' => array(
                'hostname'         => 's3.eu-central-2.wasabisys.com',
                'bucket'           => '...',
                'autocreate'       => false,
                'key'              => '...',
                'secret'           => '...',
                'region'           => 'eu-central-2',
                'use_ssl'          => true,
                'use_path_style'   => false,
                'uploadPartSize'   => '2097152000'
              )
            )
          );

Additional context, if any

1. It would be nice if such a change would be marked as a breaking change next time
2. The chart should respect the manually set configuration
3. The new options are missing uploadPartSize, which is required to be set there for some reason on S3 storage, so I can't even switch to the new configuration style