build(deps): bump sdk-core from 9.15.4 to 9.15.5 (#255)

Bumps [sdk-core](https://github.com/IBM/java-sdk-core) from 9.15.4 to 9.15.5.
- [Release notes](https://github.com/IBM/java-sdk-core/releases)
- [Changelog](https://github.com/IBM/java-sdk-core/blob/main/CHANGELOG.md)
- [Commits](IBM/java-sdk-core@9.15.4...9.15.5)

---
updated-dependencies:
- dependency-name: com.ibm.cloud:sdk-core
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

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

pom.xml

@@ -15,7 +15,7 @@
     <packaging>pom</packaging>
 
     <properties>
-        <sdk-core-version>9.15.4</sdk-core-version>
+        <sdk-core-version>9.15.5</sdk-core-version>
 
         <git-repository-name>cloudant-java-sdk</git-repository-name>