ref(boto3): Rename span origin to auto.aws.boto3

[pabloDeputter]

Description

Rename the boto3 span origin from auto.http.boto3 to auto.aws.boto3, for every boto3 span including the streamed response body child, and removes the unused get_span_origin() method from _ServiceExtension.
(todo: to be added to migration guide if we change it)

Why

1. auto.http.boto3 describes the underlying transport/integration used; boto3 spans are AWS API calls, and (in the future) the ops will be changed from http.client => rpc, db, queue.*, object.*, so it doesn't really fit anymore.
2. JS does the same and uses auto.aws.aws_sdk.

Other option

The other option is to use auto.rpc.boto3 as the default origin (since aws isn't technically part of the categories, even though JS uses it https://develop.sentry.dev/sdk/telemetry/traces/trace-origin/) and override it with the span's op for different services:

• db => auto.db.boto3
• queue.* => auto.queue.boto3
• object.* => auto.object.boto3
• streamed body child has op http.client.stream => auto.http.boto3

[github-actions]

Coverage Results 📊

✅ 56199 passed | ❌ 1 failed | ⏭️ 2872 skipped | Total: 59072 | Pass Rate: 95.14% | Execution Time: 156m 31s

📊 Comparison with Base Branch

Metric	Change
Total Tests	📉 -81870
Passed Tests	📉 -77467
Failed Tests	📈 +1
Skipped Tests	📉 -4404

✅ Patch coverage is 100.00% (1 of 1 changed executable lines covered; target 80%).
Project statement coverage is 90.07% (down 0.16 percentage points from base (6c430fb) to head (26d789e)).

Changed files with executable lines (1)

File	Patch coverage	Changed executable lines
sentry_sdk/integrations/boto3/consts.py	100.00%	1/1 covered

Coverage diff

@@            Coverage Diff             @@
##        master     #8034       +/-##
==========================================
- Coverage    90.23%    90.07%    -0.16%
==========================================
  Files          202       193        -9
  Tracked lines     26660     20932     -5728
  Branches      9926      7206     -2720
==========================================
- Hits         24055     18854     -5201
+ Misses        2605      2078      -527
+ Partials      1510      1233      -277

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Generated by Coverage Action

[sentrivana]

Please also add to MIGRATION_GUIDE.md 🙏🏻

[cursor]

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