internal/contrib: fix TestTelemetryEnabled flakiness on Windows

[hannahkm]

What does this PR do?

Allows other path separators to prevent flaking on Windows OS.

Motivation

Test was flaking in CI due to different results from Windows vs other OS's.

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

Unsure? Have a question? Request a review!

[datadog-datadog-prod-us1]

Datadog Report

Branch report: hannahkm/fix-telemetry-enabled
Commit report: e3136dc
Test service: dd-trace-go

✅ 0 Failed, 4066 Passed, 64 Skipped, 2m 45.92s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-12-19 17:14:48

Comparing candidate commit 529bfdd in PR branch hannahkm/fix-telemetry-enabled with baseline commit cec8baa in branch v2-dev.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 51 metrics, 2 unstable metrics.