chore(deps): update opentelemetry-dotnet monorepo to 1.15.1

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
OpenTelemetry (source)	1.15.0 → 1.15.1
OpenTelemetry.Exporter.InMemory (source)	1.15.0 → 1.15.1
OpenTelemetry.Exporter.OpenTelemetryProtocol (source)	1.15.0 → 1.15.1
OpenTelemetry.Extensions.Hosting (source)	1.15.0 → 1.15.1

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Release Notes

open-telemetry/opentelemetry-dotnet (OpenTelemetry)

v1.15.1

Release details: 1.15.1

• Breaking change: The Baggage API now disallows empty baggage names and
  treats baggage names and values as case sensitive, aligning with the latest
  Baggage API specification.
• Various bug fixes across OpenTelemetry.Api and OpenTelemetry SDK,
  including fixes for thread-safety, sampler edge cases, metrics precision,
  and observable instrument lifecycle handling.

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about these updates again.

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• If you want to rebase/retry this PR, check this box

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.46%. Comparing base (e1157c2) to head (0d81194).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #726   +/-   ##
=======================================
  Coverage   93.46%   93.46%           
=======================================
  Files          68       68           
  Lines        2952     2952           
  Branches      350      350           
=======================================
  Hits         2759     2759           
  Misses        135      135           
  Partials       58       58           

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