GH-2 - Upgrade to Spring Boot 3.

Upgrade to Spring Boot 3 and Java 17 as project baselines. Removed legacy JavaEE modules and replaced them by ones compatible with JakartaEE 9.

Disabled the Observability module for now as Spring Cloud Sleuth has been removed the Boot 3 compatible Spring Cloud branch and we need to migrate the module to Micrometer first.

pom.xml

@@ -12,7 +12,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.7.1</version>
+		<version>3.0.0-SNAPSHOT</version>
 		<relativePath />
 	</parent>
 
@@ -22,10 +22,9 @@
 		<module>spring-modulith-events</module>
 		<module>spring-modulith-test</module>
 		<module>spring-modulith-docs</module>
-		<module>spring-modulith-observability</module>
+		<!--<module>spring-modulith-observability</module>-->
 		<module>spring-modulith-moments</module>
 		<module>spring-modulith-starter-jpa</module>
-		<module>spring-modulith-starter-jpa-jakarta</module>
 		<module>spring-modulith-starter-test</module>
 	</modules>
 
@@ -111,6 +110,13 @@ limitations under the License.
 						<enabled>false</enabled>
 					</releases>
 				</repository>
+				<repository>
+					<id>spring-milestone</id>
+					<url>https://repo.spring.io/milestone</url>
+					<snapshots>
+						<enabled>false</enabled>
+					</snapshots>
+				</repository>
 			</repositories>
 		</profile>
 
@@ -201,8 +207,8 @@ limitations under the License.
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-compiler-plugin</artifactId>
 				<configuration>
-					<source>1.8</source>
-					<target>1.8</target>
+					<source>17</source>
+					<target>17</target>
 				</configuration>
 			</plugin>