Stash WIP of future potential use of #[diagnostic::on_unimplemented]

[clux]

Quick test of rust-lang/rust#119888 playground using

cargo +nightly run --example dynamic_watcher

Stashing this here for my own memory.
Currently does not seem to be super helpful as it doesn't give me the warning via a trait bound:

error[E0599]: the function or associated item `all_with` exists for struct `Api<MyStruct>`, but its trait bounds were not satisfied
   --> examples/dynamic_watcher.rs:33:32
    |
12  | struct MyStruct {}
    | --------------- doesn't satisfy `MyStruct: Resource`
...
33  |     let api = Api::<MyStruct>::all_with(client, &ar);
    |                                ^^^^^^^^ function or associated item cannot be called on `Api<MyStruct>` due to unsatisfied trait bounds
    |
note: if you're trying to build a new `kube::Api<MyStruct>` consider using one of the following associated functions:
      kube::Api::<K>::all_with
      kube::Api::<K>::namespaced_with
      kube::Api::<K>::default_namespaced_with
      kube::Api::<K>::all
      and 2 others
   --> /home/clux/kube/kube/kube-client/src/api/mod.rs:78:5
    |
78  |       pub fn all_with(client: Client, dyntype: &K::DynamicType) -> Self {
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
91  | /     pub fn namespaced_with(client: Client, ns: &str, dyntype: &K::DynamicType) -> Self
92  | |     where
93  | |         K: Resource<Scope = DynamicResourceScope>,
    | |__________________________________________________^
...
112 | /     pub fn default_namespaced_with(client: Client, dyntype: &K::DynamicType) -> Self
113 | |     where
114 | |         K: Resource<Scope = DynamicResourceScope>,
    | |__________________________________________________^
...
162 |       pub fn all(client: Client) -> Self {
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: the following trait bounds were not satisfied:
            `MyStruct: Resource`
note: the trait `Resource` must be implemented
   --> /home/clux/kube/kube/kube-core/src/resource.rs:33:1
    |
33  | pub trait Resource {
    | ^^^