Removing deprecated ServiceDiscoveryRetryStrategy (#1949)

Motivation:

Recently, `ServiceDiscoveryRetryStrategy` was deprecated. For 0.42
release we intend to remove it.

Modifications:

`ServiceDiscoveryRetryStrategy` and
`DefaultServiceDiscoveryRetryStrategy` have been removed.

Result:

Only the standard retry mechanism is available for `ServiceDiscoverer`
errors in `SingleAddressHttpClientBuilder` and in
`PartitionedHttpClientBuilder`.

servicetalk-http-api/src/main/java/io/servicetalk/http/api/PartitionedHttpClientBuilder.java

@@ -95,36 +95,12 @@ PartitionedHttpClientBuilder<U, R> serviceDiscoverer(
 
     /**
      * Sets a retry strategy to retry errors emitted by {@link ServiceDiscoverer}.
-     * <p>
-     * Note, calling this method will unset the value provided via
-     * {@link #retryServiceDiscoveryErrors(BiIntFunction)} if it was called before.
-     * @param retryStrategy a retry strategy to retry errors emitted by {@link ServiceDiscoverer}.
-     * @return {@code this}.
-     * @see DefaultServiceDiscoveryRetryStrategy.Builder
-     * @deprecated Use {@link #retryServiceDiscoveryErrors(BiIntFunction)} preferably with the standard utilities from
-     * {@link io.servicetalk.concurrent.api.RetryStrategies}.
-     */
-    @Deprecated
-    default PartitionedHttpClientBuilder<U, R> retryServiceDiscoveryErrors(
-            ServiceDiscoveryRetryStrategy<R, PartitionedServiceDiscovererEvent<R>> retryStrategy) {
-        throw new UnsupportedOperationException("retryServiceDiscoveryErrors accepting ServiceDiscoveryRetryStrategy" +
-                " is not supported by " + getClass().getName());
-    }
-
-    /**
-     * Sets a retry strategy to retry errors emitted by {@link ServiceDiscoverer}.
-     * <p>
-     * Note, calling this method will unset the value provided via
-     * {@link #retryServiceDiscoveryErrors(ServiceDiscoveryRetryStrategy)} if it was called before.
      * @param retryStrategy a retry strategy to retry errors emitted by {@link ServiceDiscoverer}.
      * @return {@code this}.
      * @see io.servicetalk.concurrent.api.RetryStrategies
      */
-    default PartitionedHttpClientBuilder<U, R> retryServiceDiscoveryErrors(
-            BiIntFunction<Throwable, ? extends Completable> retryStrategy) {
-        throw new UnsupportedOperationException("retryServiceDiscoveryErrors accepting BiIntFunction" +
-                " is not supported by " + getClass().getName());
-    }
+    PartitionedHttpClientBuilder<U, R> retryServiceDiscoveryErrors(
+            BiIntFunction<Throwable, ? extends Completable> retryStrategy);
 
     /**
      * Sets the maximum amount of {@link ServiceDiscovererEvent} objects that will be queued for each partition.