release: Release 4 gems

[github-actions]

This pull request prepares new gem releases for the following gems:

• opentelemetry-api 2.0.0 (was 1.6.0)
• opentelemetry-sdk 1.9.0 (was 1.8.1)
• opentelemetry-metrics-sdk 0.9.1 (was 0.9.0)
• opentelemetry-logs-sdk 0.4.0 (was 0.3.0)

For each gem, this pull request modifies the gem version and provides an initial changelog entry based on conventional commit messages. You can edit these changes before merging, to release a different version or to alter the changelog text.

• To confirm this release, merge this pull request, ensuring the "release: pending" label is set. The release script will trigger automatically on merge.
• To abort this release, close this pull request without merging.

The generated changelog entries have been copied below:

---

opentelemetry-api

v2.0.0 / 2025-09-09

• BREAKING CHANGE: Remove Span APIs for attributes and events

• ADDED: Add record_exception option for in_span

• FIXED: Remove Span APIs for attributes and events

---

opentelemetry-sdk

v1.9.0 / 2025-09-09

• ADDED: Add record_exception option for in_span

---

opentelemetry-metrics-sdk

v0.9.1 / 2025-09-09

• FIXED: Use mapping scale outside rescale logic

---

opentelemetry-logs-sdk

v0.4.0 / 2025-09-09

• BREAKING CHANGE: Add OTEL_LOGRECORD_ATTRIBUTE_* env vars. Remove OTEL_LOG_RECORD_ATTRIBUTE_* env vars.

• ADDED: Add OTEL_LOGRECORD_ATTRIBUTE_* env vars. Remove OTEL_LOG_RECORD_ATTRIBUTE_* env vars.

[fbogsany]

opentelemetry-api 2.0.0 (was 1.6.0)

We don't want to bump the major version like this.

[github-actions]

WARNING: An additional commit was added while this release PR was open.
You may need to add to the changelog, or close this PR and prepare a new one.

Commit link: 0b05b28

Message:
chore: remove references to batch processor (#1915)

[github-actions]

WARNING: An additional commit was added while this release PR was open.
You may need to add to the changelog, or close this PR and prepare a new one.

Commit link: d8d8f98

Message:
chore: regenerate from opentelemetry-proto v1.8.0 (#1921)

• chore: regenerate from opentelemetry-proto v1.8.0

• Update exporter/otlp/Rakefile

Co-authored-by: Robert robertlaurin@users.noreply.github.com

---

Co-authored-by: Robert robertlaurin@users.noreply.github.com

[kaylareopelle]

opentelemetry-api 2.0.0 (was 1.6.0)

We don't want to bump the major version like this.

I was wondering about that, @fbogsany. Even though they haven't been out long, we're removing public APIs from the opentelemetry-api gem, which according to semantic versioning is a breaking change. What do you think about adding the attributes and events APIs back and marking them as deprecated? Then we can hold the removal until we're ready to go to 2.0.

Also open to other approaches if you have another idea. I'll close this PR and we can handle the release in a different one when we make a decision.