Fixed compilation error on Java 8. Added Maven Compiler Plugin config…

…uration for Java 8 with an empty release property.

pom.xml

@@ -73,9 +73,8 @@
 	</developers>
 
 	<properties>
-		<!-- Java 8 -->
-		<maven.compiler.release>8</maven.compiler.release>
-		<maven.compiler.target>${maven.compiler.release}</maven.compiler.target>
+		<!-- Java 8 & 17 -->
+		<maven.compiler.release>17</maven.compiler.release>
 
 		<!-- Reproducible Build -->
 		<!-- See https://maven.apache.org/guides/mini/guide-reproducible-builds.html -->
@@ -146,6 +145,17 @@
 			<plugin>
 				<artifactId>maven-compiler-plugin</artifactId>
 				<executions>
+					<execution>
+						<id>default-compile</id>
+						<phase>compile</phase>
+						<goals>
+							<goal>compile</goal>
+						</goals>
+						<configuration>
+							<release>${null}<!-- keep empty to force target Java 8 --></release>
+							<target>1.8</target>
+						</configuration>
+					</execution>
 					<execution>
 						<id>compile-java-21</id>
 						<phase>compile</phase>