Bump opentelemetry-otlp from 0.31.1 to 0.32.0

[dependabot]

Bumps opentelemetry-otlp from 0.31.1 to 0.32.0.

Changelog

Sourced from opentelemetry-otlp's changelog.

Release Notes 0.32

OpenTelemetry Rust 0.32 continues to drive the Logs, Metrics, and Distributed Tracing components forward. The Logs and Metrics API and SDK remain stable, with no breaking changes in this release. The OTLP Exporters and the Distributed Tracing API/SDK remain in pre-stable states (Release-Candidate and Beta respectively), and this release introduces a small number of intentional breaking changes in those areas to prepare them for stabilization.

For detailed changelogs of individual crates, please refer to their respective changelog files. This document serves as a summary of the main changes.

Key Changes

Metrics SDK

1. Bound instruments (experimental): Added Counter::bind() and Histogram::bind() returning pre-bound measurement handles (BoundCounter<T>, BoundHistogram<T>). Bound instruments resolve the attribute-to-aggregator mapping once at bind time and cache the result, eliminating per-call HashMap lookups on the hot path. Benchmarks show ~28x speedup for counter operations and ~9x for histograms. Gated behind the experimental_metrics_bound_instruments feature flag.

2. Delta collection efficiency: Delta metrics collection now uses in-place eviction instead of draining the HashMap on every collect cycle. Stale attribute sets that received no measurements since the last collection are evicted.

3. Stable Aggregation API: Aggregation and StreamBuilder::with_aggregation() are now stable and no longer require the spec_unstable_metrics_views feature flag.

Logs

1. Tracing-span attribute enrichment (experimental): The opentelemetry-appender-tracing crate can now copy attributes from active tracing spans onto each emitted log record. ("Span" here refers to tracing::span!, not an opentelemetry::trace::Span.) Enrichment is disabled by default with zero per-span overhead, and is gated behind the new experimental_span_attributes cargo feature.

2. spec_unstable_logs_enabled removed: The capability (and the backing specification) is now stable and is enabled by default. The feature flag has been removed.

Distributed Tracing (Beta)

The Distributed Tracing API and SDK remain in beta. This release contains intentional breaking changes to clean up the public surface ahead of

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Commits

• ec289cb chore: Prepare for release v0.32.0 (#3508)
• 3ddb386 fix(metrics): reject usize::MAX as cardinality limit (#3506)
• bad0a1b feat(appender-tracing): re-gate span attribute enrichment behind experimental...
• f744509 docs: update README status table and remove deprecated crates (#3502)
• 81d5a06 chore(prometheus): restore crate to workspace (#3500)
• 5a07ce1 ci: close stale pull requests (#3499)
• cc87dd9 feat(appender-tracing): stabilize span attribute propagation (#3482)
• f290595 docs(metrics): document experimental bound instruments (#3495)
• a79eb76 fix(sdk): suppress telemetry in SimpleSpanProcessor during export (#3494)
• aa3bda3 chore(zipkin): deprecate opentelemetry-zipkin crate (#3492)
• Additional commits viewable in compare view