[GR-26993] Define our own close-like method for compatibility

* JLine 3.14+ made AbstractTerminal#close() final:
  jline/jline3@c3317bc8b7

Author: eregon

src/main/java/org/truffleruby/stdlib/readline/ConsoleHolder.java

@@ -160,7 +160,12 @@ private String getType() {
 
     public void close() {
         try {
-            readline.getTerminal().close();
+            final Terminal terminal = readline.getTerminal();
+            if (terminal instanceof PosixSysTerminalKeepSignalHandlers) {
+                ((PosixSysTerminalKeepSignalHandlers) terminal).customClose();
+            } else {
+                terminal.close();
+            }
         } catch (IOException e) {
             throw CompilerDirectives.shouldNotReachHere(e);
         }

src/main/java/org/truffleruby/stdlib/readline/PosixSysTerminalKeepSignalHandlers.java

@@ -17,6 +17,7 @@
 import java.nio.charset.Charset;
 
 import org.graalvm.shadowed.org.jline.terminal.impl.AbstractPosixTerminal;
+import org.graalvm.shadowed.org.jline.terminal.impl.AbstractTerminal;
 import org.graalvm.shadowed.org.jline.terminal.spi.Pty;
 import org.graalvm.shadowed.org.jline.utils.NonBlocking;
 import org.graalvm.shadowed.org.jline.utils.NonBlockingInputStream;
@@ -65,9 +66,9 @@ public PrintWriter writer() {
     }
     // Checkstyle: start
 
-    @Override
-    public void close() throws IOException {
-        super.close();
+    /** {@link AbstractTerminal#close()} is final in JLine 3.14+ */
+    public void customClose() throws IOException {
+        close();
         // Do not call reader.close()
         reader.shutdown();
     }