Remove `MethodDeprecation` implementation

[alexmerlin]

Feature Request

Since version 6, in Dotkernel API each handler is PSR-15 middleware responsible for handling a single request method. This means that each resource operation will have its own handler class. Therefore, MethodDeprecation no longer has a class method to attach to. Instead, you should use the ResourceDeprecation attribute on the handler class.

Q	A
New Feature	no
RFC	no
BC Break	yes

[alexmerlin]

Implemented in #469 and #470