[AIRFLOW-XXXX] Add pre-commit check for utf-8 file encoding

[feluelle]

Note: From Python 3.x onwards the explicit utf-8 header is no longer required. It is utf-8 encoded by default.

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Issue link: Document only change, no JIRA issue

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[feluelle]

Related to #7338

[mik-laj]

I want to do it using pyupgrade: #7343 I don't know if we want to duplicate tools that do the same.

[potiuk]

I think we can add it for now and replace with pyupgrade when it's ready. Pyupgrade has more things that it fixes but I see no problem with adding it now especially that it is built-in in one of the repos we have now.

[potiuk]

However we should exclude vendor files from this for sure

[potiuk]

As mentioned - for now it's a good solution especially that encodings were added in few files in the meantime. But _vendor should be excluded - similarly as for the other checks.

[mik-laj]

I don't know if adding magic comments with coding is a problem that is worth solving. It seems to me that if someone adds this comment it does not cause serious problems and we do not need a temporary solution. Instead of developing a temporary solution for a maximum of 2 weeks, you can make other contributions. I am not against this change. If you decide to finish it, I will gladly accept it. I just wanted to show the wider context of my change. Deleting the magic of comments is only an intermediate step, but it is not my goal.

[potiuk]

I think discussing it now took more time than implementing it :). I am all for intermediate solutions if they are super-simple to implement.

[potiuk]

I think you need to apply the precommit in the next push @feluelle !

[feluelle]

True. 🤦‍♂

[feluelle]

That should do it! ..now I think we should get this thing quickly merged as soon as it passes to avoid further rebases :P

[codecov-io]

Codecov Report

Merging #7347 into master will decrease coverage by 0.28%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #7347      +/-   ##
==========================================
- Coverage   86.35%   86.06%   -0.29%     
==========================================
  Files         871      871              
  Lines       40627    40627              
==========================================
- Hits        35083    34967     -116     
- Misses       5544     5660     +116

Impacted Files	Coverage Δ
.../providers/amazon/aws/operators/cloud_formation.py	100% <ø> (ø)	⬆️
...rflow/providers/mysql/operators/presto_to_mysql.py	100% <ø> (ø)	⬆️
...flow/providers/amazon/aws/hooks/cloud_formation.py	96.77% <ø> (ø)	⬆️
...ow/providers/amazon/aws/sensors/cloud_formation.py	100% <ø> (ø)	⬆️
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%> (-45.08%)	⬇️
airflow/kubernetes/refresh_config.py	50.98% <0%> (-23.53%)	⬇️
...viders/cncf/kubernetes/operators/kubernetes_pod.py	70.21% <0%> (-23.41%)	⬇️

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[potiuk]

Thanks @feluelle !