Re-add http.target to Django old sem conv server duration metric (open-telemetry#2746)

Author: lzchen

Diff for: CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Fixed
+
+- `opentelemetry-instrumentation-django` Fix regression - `http.target` re-added back to old semconv duration metrics
+  ([#2746](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2746))
+
 ## Version 1.26.0/0.47b0 (2024-07-23)
 
 ### Added

Diff for: instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware/otel_middleware.py

@@ -333,6 +333,7 @@ def process_exception(self, request, exception):
 
     # pylint: disable=too-many-branches
     # pylint: disable=too-many-locals
+    # pylint: disable=too-many-statements
     def process_response(self, request, response):
         if self._excluded_urls.url_disabled(request.build_absolute_uri("?")):
             return response
@@ -426,6 +427,10 @@ def process_response(self, request, response):
                 duration_attrs_old = _parse_duration_attrs(
                     duration_attrs, _HTTPStabilityMode.DEFAULT
                 )
+                # http.target to be included in old semantic conventions
+                target = duration_attrs.get(SpanAttributes.HTTP_TARGET)
+                if target:
+                    duration_attrs_old[SpanAttributes.HTTP_TARGET] = target
                 self._duration_histogram_old.record(
                     max(round(duration_s * 1000), 0), duration_attrs_old
                 )