[BUG] Fix credentials issues in colab/CI

[jaychia]

• We currently throw a ProviderError in colab/CI when attempting to query for S3 credentials
• To circumvent this, we need to specify anonymous=True in all s3 accesses

[codecov]

Codecov Report

Merging #1539 (bc17bff) into main (ba1eb50) will increase coverage by 10.37%.
Report is 3 commits behind head on main.
The diff coverage is 85.71%.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1539       +/-   ##
===========================================
+ Coverage   74.85%   85.22%   +10.37%     
===========================================
  Files          61       54        -7     
  Lines        6296     5131     -1165     
===========================================
- Hits         4713     4373      -340     
+ Misses       1583      758      -825     

Files	Coverage Δ
daft/io/_csv.py	94.73% <100.00%> (ø)
daft/io/_json.py	100.00% <100.00%> (ø)
daft/io/_parquet.py	100.00% <100.00%> (ø)
daft/io/common.py	88.88% <75.00%> (-3.12%)	⬇️

... and 17 files with indirect coverage changes