Change declarative config pojos from with<Prop> to set<Prop>

[jack-berg]

Related to #8402

Currently, declarative pojos have <PojoType> with<Prop>(<PropType> propName) methods for setting properties on mutable pojo types in a fluid manner. This is problematic, because with<Prop> heavily implies the the result is an immutable copy with the property changed.

This PR changes to <PojoType> set<Prop>(<PropType> propName), which I think is the best option for us:

• Model classes stay mutable. Changing to immutable instances is much more invasive. It requires constructors which know which fields are required at initialization time, and the API changes when that changes.
• Keep the fluent API. I.e. return the pojo type and not void. This means that these aren't valid java beans. But we don't need them to be java beans and the ergonomic benefit to keeping the fluent API is extremely good.
• No builders. Builders would be another option, but add to an already large API surface area. Overkill for what we're doing here.

Despite the seeming large size of the PR, there is only one meaningful file changed in this PR: https://github.com/open-telemetry/opentelemetry-java/pull/8742/changes#diff-7a86335581560379612dfc344b0c7da937cec60da747e29f4873386fd9473f2f

The rest are find/replace.

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Waiting on reviewers · refreshed 2026-08-21 22:09 UTC

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[codecov]

Codecov Report

❌ Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 91.28%. Comparing base (b421aed) to head (1b20f6a).

Files with missing lines	Patch %	Lines
...iveconfig/model/internal/SamplerModelAccessor.java	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #8742   +/-   ##
=========================================
  Coverage     91.28%   91.28%           
- Complexity    10473    10474    +1     
=========================================
  Files          1006     1006           
  Lines         28277    28277           
  Branches       3569     3569           
=========================================
+ Hits          25812    25813    +1     
  Misses         1674     1674           
+ Partials        791      790    -1     

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