aws: Drop support for AWS SDK v1 in everything except docstore

[vangent]

Updates #3489.

[codecov]

Codecov Report

Attention: Patch coverage is 87.45098% with 32 lines in your changes missing coverage. Please review.

Project coverage is 70.60%. Comparing base (ab732c4) to head (688068d).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
blob/s3blob/s3blob.go	87.45%	16 Missing and 16 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3534      +/-   ##
==========================================
- Coverage   71.38%   70.60%   -0.78%     
==========================================
  Files         113      113              
  Lines       15190    14347     -843     
==========================================
- Hits        10843    10130     -713     
+ Misses       3582     3491      -91     
+ Partials      765      726      -39     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.