Bump io.micrometer:micrometer-bom from 1.12.8 to 1.12.9 (#795)

Bumps [io.micrometer:micrometer-bom](https://github.com/micrometer-metrics/micrometer) from 1.12.8 to 1.12.9.
- [Release notes](https://github.com/micrometer-metrics/micrometer/releases)
- [Commits](micrometer-metrics/micrometer@v1.12.8...v1.12.9)

---
updated-dependencies:
- dependency-name: io.micrometer:micrometer-bom
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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gradle/libs.versions.toml

@@ -1,5 +1,5 @@
 [versions]
-micrometer = "1.12.8"
+micrometer = "1.12.9"
 micrometerContextPropagation="1.1.1"
 junit = "5.10.3"
 javaxServlet="4.0.1"