Bump io.micrometer:micrometer-bom from 1.13.6 to 1.13.8 (#3629)

Bumps [io.micrometer:micrometer-bom](https://github.com/micrometer-metrics/micrometer) from 1.13.6 to 1.13.8.
- [Release notes](https://github.com/micrometer-metrics/micrometer/releases)
- [Commits](micrometer-metrics/micrometer@v1.13.6...v1.13.8)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

build.gradle

@@ -62,7 +62,7 @@ ext {
 	kotlinCoroutinesVersion = '1.8.1'
 	log4jVersion = '2.23.1'
 	micrometerDocsVersion = '1.0.4'
-	micrometerVersion = '1.13.6'
+	micrometerVersion = '1.13.8'
 	micrometerTracingVersion = '1.3.6'
 	mockitoVersion = '5.10.0'
 	reactorVersion = '2023.0.12'