Preserve deterministic sampler rates

[MilanGarnier]

What Does This Do

Preserves configured deterministic sampler rates at double precision.

Motivation

The sampler accepted a double but retained a float, so getSampleRate()
lost configured precision.

Additional Notes

Tested with ./gradlew :dd-trace-core:test --tests datadog.trace.common.sampling.DeterministicTraceSamplerTest --rerun-tasks.

Contributor Checklist

• Applied comp: core, type: bug fix, and tag: ai generated labels.
• No CODEOWNERS or public documentation updates are needed.

Jira ticket: N/A

[datadog-datadog-prod-us1-2]

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 55.40% (-3.62%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 8e80184 | Docs | View more details | Give us feedback!}

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	14.70 s	14.70 s	[-0.9%; +0.8%] (no difference)
startup:insecure-bank:tracing:Agent	13.57 s	13.71 s	[-1.8%; -0.2%] (maybe better)
startup:petclinic:appsec:Agent	16.96 s	16.77 s	[+0.2%; +2.1%] (maybe worse)
startup:petclinic:iast:Agent	16.92 s	17.00 s	[-1.3%; +0.3%] (no difference)
startup:petclinic:profiling:Agent	16.65 s	16.87 s	[-2.4%; -0.2%] (maybe better)
startup:petclinic:sca:Agent	16.80 s	16.68 s	[-0.3%; +1.7%] (no difference)
startup:petclinic:tracing:Agent	15.56 s	16.02 s	[-6.9%; +1.1%] (no difference)

Commit: 8e80184e · CI Pipeline · Benchmarking Platform UI

---

Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.

[mhlidd]

LGTM contingent on reverting ffe-system-test-data

[mhlidd]

❓ Is this file meant to be changed?

[mhlidd]

Merged w/ master to pull in CI fixes