meta(rust): Enable resumable uploads on docs.rs

[jan-auer]

Enables the resumable-upload-api feature in package metadata for builds on
docs.rs. Currently, our private builds and the ones on docs.rs differ for this
reason.

The resumable uploads API is considered an advanced API, but still stable so it
can be documented. We're not enabling all features, since multipart is
scheduled for removal.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.34%. Comparing base (81dbdc8) to head (d17a9f5).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #684      +/-   ##
==========================================
+ Coverage   91.33%   91.34%   +0.01%     
==========================================
  Files         117      117              
  Lines       24171    24171              
==========================================
+ Hits        22077    22080       +3     
+ Misses       2094     2091       -3     

Components	Coverage Δ
Rust Backend	94.82% <ø> (ø)
Rust Client	81.70% <ø> (ø)
Python Client	93.81% <ø> (ø)

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