Update spring boot to v2.7.15 (#9295)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

dependencyManagement/build.gradle.kts

@@ -107,7 +107,7 @@ val DEPENDENCIES = listOf(
   "org.junit-pioneer:junit-pioneer:1.9.1",
   "org.objenesis:objenesis:3.3",
   // Note that this is only referenced as "org.springframework.boot" in build files, not the artifact name.
-  "org.springframework.boot:spring-boot-dependencies:2.7.14",
+  "org.springframework.boot:spring-boot-dependencies:2.7.15",
   "javax.validation:validation-api:2.0.1.Final",
   "org.snakeyaml:snakeyaml-engine:2.6"
 )

smoke-tests/images/spring-boot/build.gradle.kts

@@ -5,12 +5,12 @@ plugins {
   id("otel.java-conventions")
 
   id("com.google.cloud.tools.jib")
-  id("org.springframework.boot") version "2.7.14"
+  id("org.springframework.boot") version "2.7.15"
 }
 
 dependencies {
   implementation(platform("io.opentelemetry:opentelemetry-bom:1.0.0"))
-  implementation(platform("org.springframework.boot:spring-boot-dependencies:2.7.14"))
+  implementation(platform("org.springframework.boot:spring-boot-dependencies:2.7.15"))
 
   implementation("io.opentelemetry:opentelemetry-api")
   implementation(project(":instrumentation-annotations"))