Guix libarchive no support xar.

--- ark-20.04.1.orig/autotests/kerfuffle/loadtest.cpp	2020-12-23 08:46:15.780782601 +0800
+++ ark-20.04.1/autotests/kerfuffle/loadtest.cpp	2020-12-23 11:13:17.101724042 +0800
@@ -181,13 +181,6 @@
         qDebug() << "lz4 executable not found in path. Skipping lz4 test.";
     }
 
-    QTest::newRow("xar archive")
-            << QFINDTESTDATA("data/simplearchive.xar")
-            << QStringLiteral("simplearchive")
-            << true << false << false << false << false << 0 << Archive::Unencrypted
-            << QStringLiteral("simplearchive")
-            << QString();
-
     QTest::newRow("mimetype child of application/zip")
             << QFINDTESTDATA("data/test.odt")
             << QStringLiteral("test")
--- ark-20.04.1.orig/autotests/kerfuffle/extracttest.cpp	2020-12-23 08:46:15.780782601 +0800
+++ ark-20.04.1/autotests/kerfuffle/extracttest.cpp	2020-12-23 11:14:02.801809620 +0800
@@ -350,23 +350,6 @@
         qDebug() << "lz4 executable not found in path. Skipping lz4 test.";
     }
 
-    archivePath = QFINDTESTDATA("data/simplearchive.xar");
-    QTest::newRow("extract selected entries from a xar archive without path")
-            << archivePath
-            << QVector<Archive::Entry*> {
-                   new Archive::Entry(this, QStringLiteral("dir1/file11.txt"), QString()),
-                   new Archive::Entry(this, QStringLiteral("file4.txt"), QString())
-               }
-            << optionsNoPaths
-            << 2;
-
-    archivePath = QFINDTESTDATA("data/simplearchive.xar");
-    QTest::newRow("extract all entries from a xar archive with path")
-            << archivePath
-            << QVector<Archive::Entry*>()
-            << optionsPreservePaths
-            << 6;
-
     archivePath = QFINDTESTDATA("data/hello-1.0-x86_64.AppImage");
     QTest::newRow("extract all entries from an AppImage with path")
             << archivePath