Remove abandoned StreamSubscribe implementation

This was never properly usable without further integration, and as such
was never stabilised. It is replaced via #1449

Signed-off-by: clux <sszynrae@gmail.com>

kube-runtime/src/utils/watch_ext.rs

@@ -1,7 +1,5 @@
 #[cfg(feature = "unstable-runtime-predicates")]
 use crate::utils::predicate::{Predicate, PredicateFilter};
-#[cfg(feature = "unstable-runtime-subscribe")]
-use crate::utils::stream_subscribe::StreamSubscribe;
 use crate::{
     utils::{event_flatten::EventFlatten, event_modify::EventModify, stream_backoff::StreamBackoff},
     watcher,
@@ -128,72 +126,6 @@ pub trait WatchStreamExt: Stream {
         PredicateFilter::new(self, predicate)
     }
 
-    /// Create a [`StreamSubscribe`] from a [`watcher()`] stream.
-    ///
-    /// The [`StreamSubscribe::subscribe()`] method which allows additional consumers
-    /// of events from a stream without consuming the stream itself.
-    ///
-    /// If a subscriber begins to lag behind the stream, it will receive an [`Error::Lagged`](crate::utils::stream_subscribe::Error::Lagged)
-    /// error. The subscriber can then decide to abort its task or tolerate the lost events.
-    ///
-    /// If the [`Stream`] is dropped or ends, any [`StreamSubscribe::subscribe()`] streams
-    /// will also end.
-    ///
-    /// **NB**: This is constructor requires an [`unstable`](https://github.com/kube-rs/kube/blob/main/kube-runtime/Cargo.toml#L17-L21) feature.
-    ///
-    /// ## Warning
-    ///
-    /// If the primary [`Stream`] is not polled, the [`StreamSubscribe::subscribe()`] streams
-    /// will never receive any events.
-    ///
-    /// # Usage
-    ///
-    /// ```
-    /// use futures::{Stream, StreamExt};
-    /// use std::{fmt::Debug, sync::Arc};
-    /// use kube_runtime::{watcher, WatchStreamExt};
-    ///
-    /// fn explain_events<K, S>(
-    ///     stream: S,
-    /// ) -> (
-    ///     impl Stream<Item = Arc<Result<watcher::Event<K>, watcher::Error>>> + Send + Sized + 'static,
-    ///     impl Stream<Item = String> + Send + Sized + 'static,
-    /// )
-    /// where
-    ///     K: Clone + Debug + Send + Sync + 'static,
-    ///     S: Stream<Item = Result<watcher::Event<K>, watcher::Error>> + Send + Sized + 'static,
-    /// {
-    ///     // Create a stream that can be subscribed to
-    ///     let stream_subscribe = stream.stream_subscribe();
-    ///     // Create a subscription to that stream
-    ///     let subscription = stream_subscribe.subscribe();
-    ///
-    ///     // Create a stream of descriptions of the events
-    ///     let explain_stream = subscription.filter_map(|event| async move {
-    ///         // We don't care about lagged events so we can throw that error away
-    ///         match event.ok()?.as_ref() {
-    ///             Ok(watcher::Event::Applied(event)) => {
-    ///                 Some(format!("An object was added or modified: {event:?}"))
-    ///             }
-    ///             Ok(_) => todo!("explain other events"),
-    ///             // We don't care about watcher errors either
-    ///             Err(_) => None,
-    ///         }
-    ///     });
-    ///
-    ///     // We now still have the original stream, and a secondary stream of explanations
-    ///     (stream_subscribe, explain_stream)
-    /// }
-    /// ```
-    #[cfg(feature = "unstable-runtime-subscribe")]
-    fn stream_subscribe<K>(self) -> StreamSubscribe<Self>
-    where
-        Self: Stream<Item = Result<watcher::Event<K>, watcher::Error>> + Send + Sized + 'static,
-        K: Clone,
-    {
-        StreamSubscribe::new(self)
-    }
-
     /// Reflect a [`watcher()`] stream into a [`Store`] through a [`Writer`]
     ///
     /// Returns the stream unmodified, but passes every [`watcher::Event`] through a [`Writer`].