Remove unused arg job_detail for EstimatorBase.attach()

[yangaws]

Issue #, if available:
job detail is always fetched by sagemaker_session. So passing it as an argument to EstimatorBase.attach() does not make sense.

Description of changes:

Merge Checklist

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[codecov-io]

Codecov Report

Merging #210 into master will decrease coverage by 0.29%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master     #210     +/-   ##
=========================================
- Coverage      91%   90.71%   -0.3%     
=========================================
  Files          42       42             
  Lines        2714     2714             
=========================================
- Hits         2470     2462      -8     
- Misses        244      252      +8

Impacted Files	Coverage Δ
src/sagemaker/estimator.py	86.1% <100%> (ø)	⬆️
src/sagemaker/local/image.py	85.44% <0%> (-2.54%)	⬇️

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