test: add missing r.close() calls in REPL multiline tests

Adds missing REPL instance cleanup calls to prevent resource leaks
in test/parallel/test-repl-multiline-navigation.js. Each test now
properly closes the REPL instance after testing cursor navigation.

PR-URL: #60226
Reviewed-By: Ruben Bridgewater <[email protected]>

Author: Han5991

test/parallel/test-repl-multiline-navigation.js

@@ -81,6 +81,8 @@ tmpdir.refresh();
 
     r.input.run([{ name: 'down' }]);
     assert.strictEqual(r.cursor, 27);
+
+    r.close();
   });
 
   repl.createInternalRepl(
@@ -142,6 +144,8 @@ tmpdir.refresh();
 
     r.input.run([{ name: 'down' }]);
     assert.strictEqual(r.cursor, 55);
+
+    r.close();
   });
 
   repl.createInternalRepl(
@@ -185,6 +189,8 @@ tmpdir.refresh();
     r.input.run([{ name: 'up' }]);
     // Check that the line is properly displayed
     assert.strictEqual(r.line, 'let lineWithMistake = `I have some\nproblem with my syntax`');
+
+    r.close();
   });
 
   repl.createInternalRepl(
@@ -232,6 +238,8 @@ tmpdir.refresh();
     '  123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123,\n' +
     '  123\n' +
     ']\n'), true);
+
+    r.close();
   });
 
   repl.createInternalRepl(