Replace the OTEL-based tracing layer with tracing based layers

crates/tower/src/tracing/mod.rs

@@ -0,0 +1,27 @@
+// Copyright 2023 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+mod enrich_span;
+mod future;
+mod layer;
+mod make_span;
+mod service;
+
+pub use self::{
+    enrich_span::{enrich_span_fn, EnrichSpan},
+    future::TraceFuture,
+    layer::TraceLayer,
+    make_span::{make_span_fn, MakeSpan},
+    service::TraceService,
+};