fix(topology): remove metrics for retired components

[Jansen-w]

Summary

Remove component-scoped internal metrics after a component is removed by a successful topology reload. Registry cleanup matches both component_id and component_kind, removes counters, gauges, and histograms, and clears their metric-recency bookkeeping so a later component with the same identity starts cleanly.

Cleanup runs only after the replacement topology is installed, preserving metrics when a reload fails and the previous topology is restored.

References

None.

Vector configuration

No new configuration is required. The regression test reloads a basic source-transform-sink topology after removing the transform.

How did you test this PR?

• cargo test -p vector-core metrics::tests --no-default-features
• cargo test -p vector --lib topology_removes_metrics_for_removed_component
• cargo test -p vector --lib topology_remove_one_transform
• cargo clippy -p vector-core --lib --tests --no-default-features -- -D warnings
• cargo clippy -p vector --lib -- -D warnings
• cargo fmt --all -- --check
• cargo vdev check changelog-fragments

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. A changelog fragment is included.
• No. A maintainer will apply the no-changelog label to this PR.