Update base64 requirement from ^0.13 to ^0.20

[mohe2015]

Description

Update base64 requirement from ^0.13 to ^0.20

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov-commenter]

Codecov Report

Merging #95 (055baf1) into main (b46a73a) will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main      #95      +/-   ##
==========================================
- Coverage   42.28%   42.28%   -0.01%     
==========================================
  Files          50       50              
  Lines       28085    28086       +1     
==========================================
  Hits        11877    11877              
- Misses      16208    16209       +1     

Flag	Coverage Δ
integration	42.28% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
opensearch/src/http/transport.rs	49.60% <0.00%> (-0.20%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[Xtansia]

Please can you add an entry to CHANGELOG.md stating the version update

[dblock]

@Xtansia Are we concerned with the compatibility CI failing?

[Xtansia]

@dblock There seems to be a pathological failing for testing unreleased 1.x (also affecting #91), the tests succeed locally but are hitting resource limits when running in GitHub Actions. I've tried running them with no changes from main, but it consistently fails with

[dblock]

@dblock There seems to be a pathological failing for testing unreleased 1.x (also affecting #91), the tests succeed locally but are hitting resource limits when running in GitHub Actions. I've tried running them with no changes from main, but it consistently fails with

Want to PR removing those and open an issue for now?