otelconf: implement cardinality_limits support in PeriodicMetricReader

[sonalgaud12]

#8400

Wire cardinality_limits from PeriodicMetricReader config into the SDK via sdkmetric.WithCardinalityLimitSelector.

Adds selector implementation with per-kind, default, and SDK fallback behavior, along with tests.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.6%. Comparing base (cd417e4) to head (39d0d99).

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #8885   +/-   ##
=====================================
  Coverage   83.6%   83.6%           
=====================================
  Files        195     195           
  Lines      15962   16020   +58     
=====================================
+ Hits       13348   13406   +58     
  Misses      2140    2140           
  Partials     474     474           

Files with missing lines	Coverage Δ
otelconf/metric.go	91.6% <100.0%> (+0.8%)	⬆️
otelconf/x/metric.go	91.4% <100.0%> (+0.7%)	⬆️

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[Copilot]

Pull request overview

Implements support for cardinality_limits in PeriodicMetricReader configuration by wiring limits into the OpenTelemetry Go SDK via sdkmetric.WithCardinalityLimitSelector, including selector logic and tests in both otelconf and otelconf/x.

Changes:

• Wire PeriodicMetricReader.CardinalityLimits into the SDK periodic reader options.
• Add cardinalityLimitSelector helper implementing per-kind, default, and SDK/provider-fallback behavior.
• Add/extend unit tests for selector behavior and config wiring scenarios; update changelog entry.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
otelconf/metric.go	Adds WithCardinalityLimitSelector(...) wiring + selector helper for otelconf.
otelconf/metric_test.go	Adds reader test cases and a dedicated TestCardinalityLimitSelector.
otelconf/x/metric.go	Adds WithCardinalityLimitSelector(...) wiring + selector helper for otelconf/x.
otelconf/x/metric_test.go	Adds reader test cases and a dedicated TestCardinalityLimitSelector.
CHANGELOG.md	Documents the new cardinality_limits support.

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[Copilot]

Pull request overview

Implements support for cardinality_limits on PeriodicMetricReader configs by wiring them into the OpenTelemetry Go SDK via sdkmetric.WithCardinalityLimitSelector, ensuring per-instrument-kind and default behaviors are respected.

Changes:

• Wire PeriodicMetricReader.CardinalityLimits into sdkmetric.NewPeriodicReader options in both otelconf and otelconf/x.
• Add a cardinalityLimitSelector implementation that applies per-kind limits, then .default, then falls back to SDK/provider behavior.
• Add unit and wiring/integration tests validating selector behavior and that limits are actually applied by the SDK reader.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
otelconf/metric.go	Wires CardinalityLimits into PeriodicReader options and adds selector helper.
otelconf/metric_test.go	Adds selector tests plus an integration-style wiring test to ensure SDK behavior changes.
otelconf/x/metric.go	Mirrors otelconf wiring/selector behavior for the experimental package.
otelconf/x/metric_test.go	Mirrors selector and wiring tests for otelconf/x.
CHANGELOG.md	Documents the newly added cardinality_limits support for PeriodicMetricReader.

---

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[codeboten]

Thanks @sonalgaud12! Looks like it needs a rebase

[sonalgaud12]

@pellared can you review this, please?