Fix encoding exception when using %%capture magic

[raubitsj]

Fixes WB-8653

Description

What does the PR do?

Testing

How was this PR tested?

Checklist

• Name PR "[WB-NNNN][WB-MMMM] Add support for..." similar to entries in CHANGELOG.md
• Include reference to internal ticket "Fixes WB-NNNN" (and github issue "Fixes #NNNN" if applicable)

[kptkin]

sweet

[codecov]

Codecov Report

Merging #3310 (2ad2938) into master (66df6aa) will increase coverage by 0.06%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3310      +/-   ##
==========================================
+ Coverage   79.94%   80.01%   +0.06%     
==========================================
  Files         217      217              
  Lines       28439    28438       -1     
==========================================
+ Hits        22736    22755      +19     
+ Misses       5703     5683      -20     

Flag	Coverage Δ
functest	56.48% <100.00%> (-0.02%)	⬇️
unittest	69.32% <100.00%> (+0.07%)	⬆️

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

Impacted Files	Coverage Δ
wandb/util.py	85.83% <100.00%> (+0.10%)	⬆️
wandb/filesync/step_prepare.py	92.85% <0.00%> (-1.43%)	⬇️
wandb/sdk/internal/stats.py	67.22% <0.00%> (-0.56%)	⬇️
wandb/sdk/lib/redirect.py	86.53% <0.00%> (-0.18%)	⬇️
wandb/sdk/lib/git.py	76.35% <0.00%> (ø)
wandb/sdk/internal/internal_api.py	83.52% <0.00%> (+1.54%)	⬆️
wandb/sdk/internal/meta.py	90.74% <0.00%> (+3.08%)	⬆️
wandb/sdk/internal/artifacts.py	86.31% <0.00%> (+6.31%)	⬆️