p5-Future: update to 0.50.

0.50    2023-03-17
        [CHANGES]
        * Swap all unit tests from `Test::More` to `Test2::V0`
        * Avoids test_requires on `Test::Refcount` or `Test::Fatal`

        [BUGFIXES]
        * Fix documentation minisynopsis on `->udata`
        * Set `@CARP_NOT` so that `AWAIT_GET` rethrow appears to come from
          the right location (RT145249)

0.49    2022-10-17
        [CHANGES]
        * Big reshuffle to move most code into Future/PP.pm in order to
          support an optional Future-XS distribution too
        * Attempt to load Future::XS by preference if it is available
        * Additional unit tests for cornercases of XS implementation
        * Remember to provide the AWAIT_WAIT API method
        * Migrated Future::Queue out into its own distribution

        [BUGFIXES]
        * Bugfixes and unit tests for convergents on pre-cancelled futures
          (RT144459)

(wiz)