Fix char lsep assignment (#15065)

Fix `char eol` issue where there was still a hardcoded `\n` taking
effect on Windows.

crates/nu-command/tests/commands/platform/char_.rs

@@ -10,3 +10,13 @@ fn test_char_list_outputs_table() {
 
     assert_eq!(actual.out, "113");
 }
+
+#[test]
+fn test_char_eol() {
+    let actual = nu!(r#"
+        let expected = if ($nu.os-info.name == 'windows') { "\r\n" } else { "\n" }
+        ((char lsep) == $expected) and ((char line_sep) == $expected) and ((char eol) == $expected)
+    "#);
+
+    assert_eq!(actual.out, "true");
+}