tests/functional: Skip the screendump tests if the command is not available

It is possible nowadays to compile QEMU without pixman support - in that
case the screendump command is not available and the related tests fail.
Thus skip these tests if the screendump command could not be executed.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20250325081713.283490-2-thuth@redhat.com>
diff --git a/tests/functional/test_arm_integratorcp.py b/tests/functional/test_arm_integratorcp.py
index a85b339..4f00924 100755
--- a/tests/functional/test_arm_integratorcp.py
+++ b/tests/functional/test_arm_integratorcp.py
@@ -73,8 +73,10 @@ def test_framebuffer_tux_logo(self):
         framebuffer_ready = 'Console: switching to colour frame buffer device'
         wait_for_console_pattern(self, framebuffer_ready)
         self.vm.cmd('human-monitor-command', command_line='stop')
-        self.vm.cmd('human-monitor-command',
-                    command_line='screendump %s' % screendump_path)
+        res = self.vm.cmd('human-monitor-command',
+                          command_line='screendump %s' % screendump_path)
+        if 'unknown command' in res:
+            self.skipTest('screendump not available')
         logger = logging.getLogger('framebuffer')
 
         cpu_count = 1
diff --git a/tests/functional/test_m68k_nextcube.py b/tests/functional/test_m68k_nextcube.py
index ff773a7..13c72bd 100755
--- a/tests/functional/test_m68k_nextcube.py
+++ b/tests/functional/test_m68k_nextcube.py
@@ -32,8 +32,10 @@ def check_bootrom_framebuffer(self, screenshot_path):
         # TODO: wait for the 'displaysurface_create 1120x832' trace-event.
         time.sleep(2)
 
-        self.vm.cmd('human-monitor-command',
-                    command_line='screendump %s' % screenshot_path)
+        res = self.vm.cmd('human-monitor-command',
+                          command_line='screendump %s' % screenshot_path)
+        if 'unknown command' in res:
+            self.skipTest('screendump not available')
 
     @skipIfMissingImports("PIL")
     def test_bootrom_framebuffer_size(self):
diff --git a/tests/functional/test_mips64el_malta.py b/tests/functional/test_mips64el_malta.py
index dd37212..3cc79b7 100755
--- a/tests/functional/test_mips64el_malta.py
+++ b/tests/functional/test_mips64el_malta.py
@@ -155,8 +155,10 @@ def do_test_i6400_framebuffer_logo(self, cpu_cores_count):
         framebuffer_ready = 'Console: switching to colour frame buffer device'
         self.wait_for_console_pattern(framebuffer_ready)
         self.vm.cmd('human-monitor-command', command_line='stop')
-        self.vm.cmd('human-monitor-command',
-                    command_line='screendump %s' % screendump_path)
+        res = self.vm.cmd('human-monitor-command',
+                          command_line='screendump %s' % screendump_path)
+        if 'unknown command' in res:
+            self.skipTest('screendump not available')
         logger = logging.getLogger('framebuffer')
 
         match_threshold = 0.95