Set default maven-compiler-plugin release to 12

pom.xml

@@ -234,6 +234,13 @@
         <groupId>io.github.zlika</groupId>
         <artifactId>reproducible-build-maven-plugin</artifactId>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <release>12</release>
+        </configuration>
+      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-enforcer-plugin</artifactId>