[AIRFLOW-6821] - Success callback not called when task marked as success from UI

[saurabhdhupar]

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Issue link: AIRFLOW-6821

Make sure to mark the boxes below before creating PR: [x]

• [ x] Description above provides context of the change
• [x ] Commit message/PR title starts with [AIRFLOW-NNNN]. AIRFLOW-NNNN = JIRA ID^*
• [ x] Unit tests coverage for changes (not needed for documentation changes)
• [ x] Commits follow "How to write a good git commit message"
• [ x] Relevant documentation is updated including usage instructions.
• [ x] I will engage committers as explained in Contribution Workflow Example.

^* For document-only changes commit message can start with [AIRFLOW-XXXX].

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Read the Pull Request Guidelines for more information.

[boring-cyborg]

Congratulations on your first Pull Request and welcome to the Apache Airflow community! If you have any issues or are unsure about any anything please check our Contribution Guide (https://github.com/apache/airflow/blob/master/CONTRIBUTING.rst)
Here are some useful points:

• Pay attention to the quality of your code (flake8, pylint and type annotations). Our pre-commits will help you with that.
• In case of a new feature add useful documentation (in docstrings or in docs/ directory). Adding a new operator? Check this short guide Consider adding an example DAG that shows how users should use it.
• Consider using Breeze environment for testing locally, it’s a heavy docker but it ships with a working Airflow and a lot of integrations.
• Be patient and persistent. It might take some time to get a review or get the final approval from Committers.
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[codecov-io]

Codecov Report

Merging #7438 into master will increase coverage by 53.41%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           master    #7438       +/-   ##
===========================================
+ Coverage   32.95%   86.37%   +53.41%     
===========================================
  Files         878      878               
  Lines       41219    41222        +3     
===========================================
+ Hits        13584    35604    +22020     
+ Misses      27635     5618    -22017

Impacted Files	Coverage Δ
airflow/jobs/local_task_job.py	90.12% <100%> (+67.04%)	⬆️
airflow/kubernetes/volume_mount.py	44.44% <0%> (-55.56%)	⬇️
airflow/kubernetes/volume.py	52.94% <0%> (-47.06%)	⬇️
airflow/kubernetes/pod_launcher.py	47.18% <0%> (-39.44%)	⬇️
...viders/cncf/kubernetes/operators/kubernetes_pod.py	69.38% <0%> (-25.52%)	⬇️
airflow/kubernetes/refresh_config.py	50.98% <0%> (-23.53%)	⬇️
airflow/bin/airflow	84.61% <0%> (ø)	⬆️
airflow/plugins_manager.py	86.95% <0%> (+0.72%)	⬆️
airflow/bin/cli.py	94.73% <0%> (+2.1%)	⬆️
airflow/executors/celery_executor.py	88.51% <0%> (+3.37%)	⬆️
... and 749 more

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