Remove jvmti wallclock sampler for none J9 VMs

[zhengyu123]

What does this PR do?:
Remove JVMTI based wallclock support for none J9 VMs

Motivation:
JVMTI based wallclock sampler is not very useful

• Captured thread may have already exited when sampling
• Cannot properly propagate context

Remove it and related tests to reduce maintenance cost.

Additional Notes:

How to test the change?:

• CI tests

For Datadog employees:

• If this PR touches code that signs or publishes builds or packages, or handles
  credentials of any kind, I've requested a review from @DataDog/security-design-and-guidance.
• This PR doesn't touch any of that.
• JIRA: PROF-14004

Unsure? Have a question? Request a review!

[dd-octo-sts]

CI Test Results

Run: #23163367922 | Commit: 1d47ada | Duration: 10m 16s (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: 2026-03-16 20:16:27 UTC

[pr-commenter]

Integration Tests

✅ All 40 integration tests passed

📊 Dashboard · 👷 Pipeline · 📦 d1348d7c

[jbachorik]

Please, follow up in dd-trace-java and remove the experimental config key to enable JVMTI wallclock engine.