Make Falcon instrumentation compatible with Falcon >=3 (#607)

* Make Falcon  instrumentation compatible with Falcon >=3

Replace falcon.api.Request -> falcon.Request which exists on both Falcon 2 & 3

* Update package.py

* Update CHANGELOG.md

* update tox.ini

* revert changes to tox.ini to test failures

* Update package.py

Co-authored-by: Owais Lone <owais@users.noreply.github.com>

CHANGELOG.md

@@ -30,6 +30,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#595](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/595))
 
 ### Changed
+- `opentelemetry-instrumentation-falcon` added support for Falcon 3.
+  ([#607](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/607))
 - `opentelemetry-instrumentation-tornado` properly instrument work done in tornado on_finish method.
   ([#499](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/499))
 - `opentelemetry-instrumentation` Fixed cases where trying to use an instrumentation package without the

instrumentation/opentelemetry-instrumentation-falcon/src/opentelemetry/instrumentation/falcon/__init__.py

@@ -126,7 +126,7 @@ def response_hook(span, req, resp):
 
 _excluded_urls = get_excluded_urls("FALCON")
 _traced_request_attrs = get_traced_request_attrs("FALCON")
-_response_propagation_setter = FuncSetter(falcon.api.Response.append_header)
+_response_propagation_setter = FuncSetter(falcon.Response.append_header)
 
 
 class FalconInstrumentor(BaseInstrumentor):