net-mgmt/gping: Fix build with rust 1.74

Import upstream patch [1] to fix the following error:
error[E0283]: type annotations needed
   --> gping/src/main.rs:486:26
    |
486 |                         .constraints(
    |                          ^^^^^^^^^^^ cannot infer type of the type parameter `C` declared on the method `constraints`
...
491 |                                 .as_ref(),
    |                                  ------ type must be known at this point
    |
    = note: multiple `impl`s satisfying `Vec<Constraint>: AsRef<_>` found in the `alloc` crate:
            - impl<T, A> AsRef<Vec<T, A>> for Vec<T, A>
              where A: Allocator;
            - impl<T, A> AsRef<[T]> for Vec<T, A>
              where A: Allocator;
help: consider specifying the generic argument
    |
486 |                         .constraints::<&T>(
    |                                     ++++++

[1] https://github.com/orf/gping/commit/7ad129c979b48cbea8b1c64ddf37e71da7f00d13

PR:		275243
Approved by:	portmgr (build fix blanket)