Revert "Merge pull request #1067 from phax/java17-base"

This reverts commit f6b6c0a36e, reversing
changes made to d8313dae20.

Mustang-CLI/pom.xml

@@ -13,7 +13,7 @@
     <packaging>jar</packaging>
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.release>${java.version}</maven.compiler.release>
+        <maven.compiler.release>11</maven.compiler.release>
     </properties>
     <dependencies>
         <!-- compile dependencies -->
@@ -118,8 +118,8 @@
                     <!-- http://stackoverflow.com/questions/574594/how-can-i-create-an-executable-jar-with-dependencies-using-maven
                              mvn clean compile assembly:single -->
                     <!-- or whatever version you use -->
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
+                    <source>11</source>
+                    <target>11</target>
                 </configuration>
             </plugin>
             <plugin>
@@ -209,7 +209,7 @@
                         <configuration>
                             <toolchains>
                                 <jdk>
-                                    <version>${java.version}</version>
+                                    <version>11</version>
                                     <vendor>adopt</vendor>
                                 </jdk>
                             </toolchains>