Remove APIs deprecated since v 4.4.0 (#6722)

The deprecated APIs are not supposed to stay around for ever. The
purpose of deprecation is to eventually remove.

arrow-flight/src/utils.rs

@@ -17,8 +17,7 @@
 
 //! Utilities to assist with reading and writing Arrow data as Flight messages
 
-use crate::{FlightData, IpcMessage, SchemaAsIpc, SchemaResult};
-use bytes::Bytes;
+use crate::{FlightData, SchemaAsIpc};
 use std::collections::HashMap;
 use std::sync::Arc;
 
@@ -104,41 +103,6 @@ pub fn flight_data_to_arrow_batch(
         })?
 }
 
-/// Convert a `Schema` to `SchemaResult` by converting to an IPC message
-#[deprecated(
-    since = "4.4.0",
-    note = "Use From trait, e.g.: SchemaAsIpc::new(schema, options).try_into()"
-)]
-pub fn flight_schema_from_arrow_schema(
-    schema: &Schema,
-    options: &IpcWriteOptions,
-) -> Result<SchemaResult, ArrowError> {
-    SchemaAsIpc::new(schema, options).try_into()
-}
-
-/// Convert a `Schema` to `FlightData` by converting to an IPC message
-#[deprecated(
-    since = "4.4.0",
-    note = "Use From trait, e.g.: SchemaAsIpc::new(schema, options).into()"
-)]
-pub fn flight_data_from_arrow_schema(schema: &Schema, options: &IpcWriteOptions) -> FlightData {
-    SchemaAsIpc::new(schema, options).into()
-}
-
-/// Convert a `Schema` to bytes in the format expected in `FlightInfo.schema`
-#[deprecated(
-    since = "4.4.0",
-    note = "Use TryFrom trait, e.g.: SchemaAsIpc::new(schema, options).try_into()"
-)]
-pub fn ipc_message_from_arrow_schema(
-    schema: &Schema,
-    options: &IpcWriteOptions,
-) -> Result<Bytes, ArrowError> {
-    let message = SchemaAsIpc::new(schema, options).try_into()?;
-    let IpcMessage(vals) = message;
-    Ok(vals)
-}
-
 /// Convert `RecordBatch`es to wire protocol `FlightData`s
 pub fn batches_to_flight_data(
     schema: &Schema,