Fix spring-kafka-3.x: use Spring Boot 3.2.12 BOM, test 3.1-3.3

Spring Kafka 3.1+ requires Spring Framework 6.1 (ClassFormatException).
Spring Boot 3.1 still uses Spring Framework 6.0, so Spring Boot 3.2+ BOM
is needed to manage consistent 6.1 versions.

Verified locally: 3.1.4, 3.2.10, 3.3.7 all passed.

Author: wu-sheng

test/plugin/scenarios/spring-kafka-3.x-scenario/pom.xml

@@ -31,13 +31,25 @@
         <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
         <test.framework.version>3.0.0</test.framework.version>
         <log4j.version>2.6.2</log4j.version>
-        <spring.boot.version>3.0.13</spring.boot.version>
+        <spring.boot.version>3.2.12</spring.boot.version>
         <kafka-version>3.3.2</kafka-version>
         <okhttp-version>3.0.0</okhttp-version>
     </properties>
 
     <name>skywalking-spring-kafka-3.x-scenario</name>
 
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>${spring.boot.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>

test/plugin/scenarios/spring-kafka-3.x-scenario/support-version.list

@@ -15,5 +15,8 @@
 # limitations under the License.
 
 # Spring Kafka 3.x requires Spring Boot 3.x / JDK 17+
-# TODO: 3.1+ needs investigation — app fails to start with overridden spring.boot.version
-3.0.17
+# This scenario uses Spring Boot 3.1.12 BOM (Spring Framework 6.1).
+# spring-kafka 3.0.x not tested here (needs Spring Boot 3.0 — covered by separate scenario if needed).
+3.1.4
+3.2.10
+3.3.7