Bump io.micrometer:micrometer-registry-prometheus from 1.10.3 to 1.12.1

Bumps [io.micrometer:micrometer-registry-prometheus](https://github.com/micrometer-metrics/micrometer) from 1.10.3 to 1.12.1.
- [Release notes](https://github.com/micrometer-metrics/micrometer/releases)
- [Commits](micrometer-metrics/micrometer@v1.10.3...v1.12.1)

---
updated-dependencies:
- dependency-name: io.micrometer:micrometer-registry-prometheus
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle

@@ -87,7 +87,7 @@ dependencies {
 
     compile('org.springframework.boot:spring-boot-starter-web')
     compile('org.springframework.boot:spring-boot-starter-actuator')
-    compile('io.micrometer:micrometer-registry-prometheus:1.10.3')
+    compile('io.micrometer:micrometer-registry-prometheus:1.12.1')
     compile('io.micrometer:micrometer-spring-legacy:1.3.20')
     compileOnly("org.springframework.boot:spring-boot-configuration-processor")