Update Rust crate metrics-exporter-prometheus to v0.15.3

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
metrics-exporter-prometheus	workspace.dependencies	patch	0.15.1 -> 0.15.3

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Release Notes

metrics-rs/metrics (metrics-exporter-prometheus)

### [`v0.15.3`](https://togithub.com/metrics-rs/metrics/compare/metrics-exporter-prometheus-v0.15.2...metrics-exporter-prometheus-v0.15.3) [Compare Source](https://togithub.com/metrics-rs/metrics/compare/metrics-exporter-prometheus-v0.15.2...metrics-exporter-prometheus-v0.15.3) ### [`v0.15.2`](https://togithub.com/metrics-rs/metrics/compare/metrics-exporter-prometheus-v0.15.1...metrics-exporter-prometheus-v0.15.2) [Compare Source](https://togithub.com/metrics-rs/metrics/compare/metrics-exporter-prometheus-v0.15.1...metrics-exporter-prometheus-v0.15.2)

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