Bump com.azure:azure-identity from 1.14.2 to 1.15.3

Bumps [com.azure:azure-identity](https://github.com/Azure/azure-sdk-for-java) from 1.14.2 to 1.15.3.
- [Release notes](https://github.com/Azure/azure-sdk-for-java/releases)
- [Commits](Azure/azure-sdk-for-java@azure-identity_1.14.2...azure-identity_1.15.3)

---
updated-dependencies:
- dependency-name: com.azure:azure-identity
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 spring-boot = '3.4.3'
 
 aws-msk-auth = '2.3.0'
-azure-identity = '1.14.2'
+azure-identity = '1.15.4'
 
 apache-commons-lang3 = '3.12.0'
 apache-commons-io = '2.18.0'