www/ruby-multipart-post: update to 2.2.3

2.2.0 (2022-06-03)

Added

* Add the ability to set Content-ID header for ParamPart #62
* Allow mixed key types for parts headers #79

Changed

* Refactor Parts into a Multipart::Post namespace #65
* Use mutable strings where needed #70
* Use frozen_string_literal everywhere #78

2.2.1 (not released)

2.2.2 (2022-06-09)

* Drop Ruby 2.5 or earlier

2.2.3 (2022-06-10)

* Add support for Ruby back to 2.3.

(taca)