Adds version for kotlin-maven-plugin

See gh-1218

Author: spencergibb

spring-cloud-function-context/pom.xml

@@ -152,6 +152,7 @@
 			<plugin>
 				<artifactId>kotlin-maven-plugin</artifactId>
 				<groupId>org.jetbrains.kotlin</groupId>
+				<version>1.9.25</version>
 				<executions>
 					<execution>
 						<id>compile</id>

spring-cloud-function-kotlin/pom.xml

@@ -86,6 +86,7 @@
 			<plugin>
 				<artifactId>kotlin-maven-plugin</artifactId>
 				<groupId>org.jetbrains.kotlin</groupId>
+				<version>1.9.25</version>
 				<executions>
 					<execution>
 						<id>test-compile</id>

spring-cloud-function-samples/function-sample-kotlin-web/pom.xml

@@ -72,6 +72,7 @@
 			<plugin>
 				<groupId>org.jetbrains.kotlin</groupId>
 				<artifactId>kotlin-maven-plugin</artifactId>
+				<version>1.9.25</version>
 				<configuration>
 					<args>
 						<arg>-Xjsr305=strict</arg>