Bump software.amazon.awssdk:bom from 2.22.9 to 2.23.15 in /plugins

Bumps software.amazon.awssdk:bom from 2.22.9 to 2.23.15.

---
updated-dependencies:
- dependency-name: software.amazon.awssdk:bom
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

plugins/DDBEndPoint/build.gradle

@@ -7,7 +7,7 @@ repositories {
 dependencies {
     implementation "com.google.code.gson:gson:${gson_version}"
     implementation "org.pytorch:torchserve-plugins-sdk:${torchserve_sdk_version}"
-    implementation platform('software.amazon.awssdk:bom:2.22.9')
+    implementation platform('software.amazon.awssdk:bom:2.23.15')
     implementation 'software.amazon.awssdk:dynamodb-enhanced'
     implementation 'org.codehaus.groovy:groovy-all:2.3.11'
     testImplementation "org.testng:testng:${testng_version}"