Add template_fields to S3KeySensorAsync

[kaxil]

closes #362

[codecov]

Codecov Report

Merging #373 (549c446) into main (ccb044d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #373   +/-   ##
=======================================
  Coverage   96.76%   96.76%           
=======================================
  Files          56       56           
  Lines        2903     2904    +1     
=======================================
+ Hits         2809     2810    +1     
  Misses         94       94           

Impacted Files	Coverage Δ
astronomer/providers/amazon/aws/sensors/s3.py	100.00% <100.00%> (ø)

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