[Serializer] options to encode/decode with JSON

[llaville]

Hello,

I think that the documentation is wrong about json_encode_options and json_decode_options

We actually can read at https://github.com/symfony/symfony-docs/blob/7.1/components/serializer.rst?plain=1#L1008-L1009

``json_encode_options``          `$flags`_ passed to :phpfunction:`json_decode` function.                                                    ``0``
``json_decode_options``          `$flags`_ passed to :phpfunction:`json_encode` function.                                                    ``\JSON_PRESERVE_ZERO_FRACTION``

Should it be rather the opposite ?

``json_encode_options``          `$flags`_ passed to :phpfunction:`json_encode` function.                                                    ``0``
``json_decode_options``          `$flags`_ passed to :phpfunction:`json_decode` function.                                                    ``\JSON_PRESERVE_ZERO_FRACTION``

[xabbuh]

I think we need to swap the option names as the default values in the right column already match the descriptions.