Cancellation of HTTP triggers waiting for python language workers does not work

#### Check for a solution in the Azure portal
For issues in production, please check for a solution to common issues in the Azure portal before opening a bug. In the Azure portal, navigate to your function app, select `Diagnose and solve problems` from the left, and view relevant dashboards before opening your issue.

#### Investigative information

Please provide the following:

- Timestamp: 2021-11-08T16:46:57.915Z
- Function App version: mcr.microsoft.com/azure-functions/python:3.0-python3.8-appservice
- Function App name:
- Function name(s) (as appropriate):
- Invocation ID: fa416bc3-f801-45db-939a-2145fcef7bee
- Region: West Europe

#### Repro steps

Provide the steps required to reproduce the problem:

1. Create a function app with 2 functions
2. trigger function 1 that will have a long IO operation and will take the language worker
3. trigger function 2 which is a HTTP one multiple times and cancel requests before they are handled by language worker

#### Expected behavior

Provide a description of the expected behavior.

HTTP-triggered Function invocations waiting for language worker should not be processed if client closed the request while function is waiting in queue.

#### Actual behavior

Provide a description of the actual behavior observed.

HTTP function executes long after client gave up waiting and closed the connection.

#### Known workarounds

Provide a description of any known workarounds.

In C# we can get a cancellation token from request context. but here the request sits in function host and arrives to python worker afer seconds or minutes. No workaround known.

#### Related information

Provide any related information

* Programming language used: Python
* Links to source: n/a
* Bindings used: none, HTTP trigger