fix(celery): Do not send extra check-in

[sentrivana]

When using the RedBeatScheduler, we're sending an extra in-progress check-in at scheduler start. Since this is never followed by an ok or error check-in, the check-in is marked as timed out in Sentry.

We're patching the scheduler's maybe_due, which (as the name implies) might not end up executing the task. This is indeed what seems to be happening -- maybe_due is run when the scheduler starts, but without scheduling the task. We don't check whether maybe_due actually ended up scheduling anything and always fire an in-progress check-in.

Patching the scheduler's apply_async instead.

Closes #4392

[codecov]

❌ 28 Tests Failed:

Tests completed	Failed	Passed	Skipped
2000	28	1972	18

View the top 3 failed test(s) by shortest run time

tests.integrations.aws_lambda.test_aws_lambda::test_headers[no headers]

Stack Traces | 0s run time

.../integrations/aws_lambda/test_aws_lambda.py:70: in test_environment
    LocalLambdaStack.wait_for_stack()
.../integrations/aws_lambda/utils.py:221: in wait_for_stack
    raise TimeoutError(
E   TimeoutError: AWS SAM failed to start within 60 seconds. (Maybe Docker is not running?)

tests.integrations.aws_lambda.test_aws_lambda::test_timeout_error

Stack Traces | 0s run time

.../integrations/aws_lambda/test_aws_lambda.py:70: in test_environment
    LocalLambdaStack.wait_for_stack()
.../integrations/aws_lambda/utils.py:221: in wait_for_stack
    raise TimeoutError(
E   TimeoutError: AWS SAM failed to start within 60 seconds. (Maybe Docker is not running?)

tests.integrations.aws_lambda.test_aws_lambda::test_trace_continuation

Stack Traces | 0s run time

.../integrations/aws_lambda/test_aws_lambda.py:70: in test_environment
    LocalLambdaStack.wait_for_stack()
.../integrations/aws_lambda/utils.py:221: in wait_for_stack
    raise TimeoutError(
E   TimeoutError: AWS SAM failed to start within 60 seconds. (Maybe Docker is not running?)

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[sl0thentr0py]

looks legit, don't know all underlying details

[antonpirker]

Looks good. Tested it with my example project and it does not what it should. (which is having only one check-in for in_progress and ok)