enhancement(prometheus_remote_write sink): Add acknowledgements suppo…

…rt (#13755)

As far as I can tell, this sink actually has support present, but not enableable
with any configuration.

src/sinks/prometheus/remote_write.rs

@@ -95,6 +95,14 @@ pub struct RemoteWriteConfig {
 
     #[configurable(derived)]
     pub auth: Option<Auth>,
+
+    #[configurable(derived)]
+    #[serde(
+        default,
+        deserialize_with = "crate::serde::bool_or_struct",
+        skip_serializing_if = "crate::serde::skip_serializing_if_default"
+    )]
+    pub acknowledgements: AcknowledgementsConfig,
 }
 
 inventory::submit! {
@@ -176,7 +184,7 @@ impl SinkConfig for RemoteWriteConfig {
     }
 
     fn acknowledgements(&self) -> Option<&AcknowledgementsConfig> {
-        None
+        Some(&self.acknowledgements)
     }
 }