fix: avoid eager string alloc in setContextAttributesByIdAndBytes validation

[jbachorik]

What does this PR do?

Replace Objects.requireNonNull(utf8[i], "utf8[" + i + "]") with a plain null check so the string concatenation only happens when actually throwing. The original form evaluated the message argument eagerly on every loop iteration — including all non-null cases in the happy path — allocating a string per slot per call.

Motivation

setContextAttributesByIdAndBytes is a hot-path method (vthread mount/unmount reapply). Allocation in its validation loop defeats the purpose of the allocation-free API.

Test plan

• Existing TagContextTest covers the validation path (null slot throws NPE, oversized bytes throws IAE)
• No behaviour change: semantics are identical — NPE with the same message, same condition

[datadog-datadog-prod-us1]

✨ Fix all issues with BitsAI

⚠️ Warnings

🚦 14 Pipeline jobs failed

DataDog/java-profiler | benchmarks-candidate-aarch64: [alloc]     

DataDog/java-profiler | benchmarks-candidate-aarch64: [cpu,wall,alloc,memleak]     

DataDog/java-profiler | benchmarks-candidate-aarch64: [cpu,wall]     

View all 14 failed jobs.

Useful? React with 👍 / 👎

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 0b5dd82 | Docs | Datadog PR Page | Give us feedback!}

[dd-octo-sts]

CI Test Results

Run: #27782406906 | Commit: e53f1ef | Duration: 19m 20s (longest job)

✅ All 32 test jobs passed

Status Overview

JDK	glibc-aarch64/debug	glibc-amd64/debug	musl-aarch64/debug	musl-amd64/debug
8	-	✅	-	-
8-ibm	-	✅	-	-
8-j9	✅	✅	-	-
8-librca	-	-	✅	✅
8-orcl	-	✅	-	-
11	-	✅	-	-
11-j9	✅	✅	-	-
11-librca	-	-	✅	✅
17	✅	✅	-	-
17-graal	✅	✅	-	-
17-j9	✅	✅	-	-
17-librca	-	-	✅	✅
21	✅	✅	-	-
21-graal	✅	✅	-	-
21-librca	-	-	✅	✅
25	✅	✅	-	-
25-graal	✅	✅	-	-
25-librca	-	-	✅	✅

Legend: ✅ passed | ❌ failed | ⚪ skipped | 🚫 cancelled

Summary: Total: 32 | Passed: 32 | Failed: 0

---

Updated: 2026-06-18 19:20:36 UTC