chore(deps): bump software.amazon.awssdk:core

Bumps software.amazon.awssdk:core from 2.26.25 to 2.28.6.

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

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

Author: dependabot[bot]

TestVectors/runtimes/java/build.gradle.kts

@@ -95,7 +95,7 @@ dependencies {
     implementation(platform("software.amazon.awssdk:bom:2.26.25"))
     implementation("software.amazon.awssdk:dynamodb")
     implementation("software.amazon.awssdk:dynamodb-enhanced")
-    implementation("software.amazon.awssdk:core:2.26.25")
+    implementation("software.amazon.awssdk:core:2.28.6")
     implementation("software.amazon.awssdk:kms")
     testImplementation("com.amazonaws:DynamoDBLocal:2.+")
     // This is where we gather the SQLLite files to copy over