internal/stableconfig: Report config ID to telemetry

[mtoffl01]

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What does this PR do?

Motivation

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.
• New code is free of linting errors. You can check this by running golangci-lint run locally.
• 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.

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[pr-commenter]

Benchmarks

Benchmark execution time: 2025-06-10 18:35:04

Comparing candidate commit 98cab07 in PR branch mtoff/scfg_config_id with baseline commit bec204b in branch main.

Found 0 performance improvements and 3 performance regressions! Performance is the same for 21 metrics, 0 unstable metrics.

scenario:BenchmarkMetrics/count/get-handle-24

• 🟥 execution_time [+5.988ns; +7.672ns] or [+2.019%; +2.587%]

scenario:BenchmarkMetrics/distribution/get-handle-24

• 🟥 execution_time [+4.447ns; +5.413ns] or [+2.003%; +2.438%]

scenario:BenchmarkMetrics/rate/get-handle-24

• 🟥 execution_time [+7.015ns; +10.485ns] or [+2.336%; +3.491%]