feat(python-client): Add Sentry span instrumentation for storage operations

[jan-auer]

This adds Sentry tracing spans to the Python client, so every request to Objectstore shows up in a trace, not just as an anonymous HTTP call. Note that this requires span streaming in the surrounding application!

Each public method that talks to Objectstore now opens a span under the objectstore.* op namespace: put, get, head, delete, the multipart methods, mint_token, and presigned_object_url. Spans always run; the Sentry SDK turns them into cheap no-ops when it is uninitialized or the transaction is unsampled.

Each span carries the usecase, the scope components, and operation-specific data (sizes, compression, found, upload IDs, and so on).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.31%. Comparing base (af3c793) to head (a3773e8).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #602      +/-   ##
==========================================
- Coverage   88.51%   88.31%   -0.21%     
==========================================
  Files         104       94      -10     
  Lines       17237    16527     -710     
==========================================
- Hits        15258    14595     -663     
+ Misses       1979     1932      -47     

Components	Coverage Δ
Rust Backend	92.52% <ø> (ø)
Rust Client	81.97% <ø> (ø)
Python Client	∅ <ø> (∅)

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[jan-auer]

@lcian pointed out that we need to use a new API for this to work in span streaming. Since most our services are switched over, we'll do this unconditionally.

More info on:

• https://docs.sentry.io/platforms/python/tracing/streamed-spans/#enable-stream-mode
• https://docs.sentry.io/platforms/python/tracing/streamed-spans/migration-guide/

[lcian]

LGTM

[lcian]

Launchpad isn't using span streaming yet apparently, so for that service we won't have the spans.

Edit: well, they need to upgrade the SDK if they want to use this new version of our client, so they'll have to migrate at that point :)

[jan-auer]

they'll have to migrate at that point

it's not obligated to adopt span streaming, but given this is an internal service, we have an incentive to. I'm OK with not having spans there until they migrate.