feat(attributes): Add session.id attribute

[Lms24]

This PR proposes adding a session.id attribute, exactly as specified by OTel. SDKs can add this attribute to outgoing telemetry so that users can query on it product-side.

For now, I didn't yet include the session.previous_id attribute because I'm yet unsure if we want to build anything around it but happy to add it as well.

[github-actions]

Semver Impact of This PR

🟡 Minor (new features)

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New Features ✨

Attributes

• Add session.id attribute by Lms24 in #412

• Add app.vitals.start.prewarmed attribute by itaybre in #379
• Add and deprecate runtime context attributes by markushi in #383
• Add Android Runtime (ART) GC and memory attributes by markushi in #382
• Add db.stored_procedure.name and ensure span name attribute consistency by Lms24 in #398
• Add Cloudflare SDK attributes by JPeer264 in #392

Other

• Add missing GCP and FaaS attributes by ericapisani in #403

Bug Fixes 🐛

• (cloudfare) Add missing visibility attributes by markushi in #408

Internal Changes 🔧

• (deps-dev) Bump vitest from 3.2.4 to 4.1.0 by dependabot in #409

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