Remove usages of deprecated description and replace by name in start_span() calls.

[antonpirker]

Replace the deprecated description parameter in all calls to start_span() and start_child and replace it with the new name parameter.

This PR is blocked by this one that deprecates description: #3524

Fixes #3521

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.

Project coverage is 84.25%. Comparing base (b1b16b0) to head (b74c94a).
Report is 1 commits behind head on master.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
sentry_sdk/integrations/langchain.py	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3525      +/-   ##
==========================================
+ Coverage   84.20%   84.25%   +0.05%     
==========================================
  Files         136      136              
  Lines       13900    13900              
  Branches     2940     2940              
==========================================
+ Hits        11705    11712       +7     
+ Misses       1465     1458       -7     
  Partials      730      730              

Files with missing lines	Coverage Δ
sentry_sdk/ai/monitoring.py	88.57% <100.00%> (ø)
sentry_sdk/integrations/aiohttp.py	85.16% <ø> (ø)
sentry_sdk/integrations/anthropic.py	83.01% <ø> (ø)
sentry_sdk/integrations/arq.py	91.45% <ø> (ø)
sentry_sdk/integrations/asyncio.py	90.19% <ø> (ø)
sentry_sdk/integrations/asyncpg.py	89.38% <ø> (ø)
sentry_sdk/integrations/boto3.py	83.11% <ø> (ø)
sentry_sdk/integrations/celery/__init__.py	91.22% <ø> (ø)
sentry_sdk/integrations/clickhouse_driver.py	91.66% <ø> (ø)
sentry_sdk/integrations/cohere.py	78.63% <ø> (ø)
... and 28 more

... and 2 files with indirect coverage changes