test: Close dialogs before next page interactions

Selecting a new action from the main page while a dialog is open only
worked with our `ph_mouse()` cheat, not with proper clicks.

test/check-machines-disks

@@ -214,6 +214,8 @@ class TestMachinesDisks(machineslib.VirtualMachinesCase):
         openDialog("sda")
         b.wait_visible("#vm-subVmTest1-disks-sda-edit-bus-type:disabled")
         b.wait_visible("#vm-subVmTest1-disks-sda-edit-cache-mode:disabled")
+        b.click("#vm-subVmTest1-disks-sda-edit-dialog button[aria-label='Close']")
+        b.wait_not_present("#vm-subVmTest1-disks-sda-edit-dialog")
 
         # Disks on non-persistent VM cannot be edited
         m.execute("virsh undefine subVmTest1")

test/check-machines-lifecycle

@@ -355,6 +355,8 @@ class TestMachinesLifecycle(machineslib.VirtualMachinesCase):
         b.set_input_text("#rename-dialog-new-name", "new")
         b.click("#rename-dialog-confirm")
         b.wait_in_text(".pf-v5-c-modal-box__body .pf-v5-c-alert.pf-m-danger", "Can't rename domain to itself")
+        b.click(".pf-v5-c-modal-box button:contains('Cancel')")
+        b.wait_not_present(".pf-v5-c-modal-box")
 
         self.goToVmPage("new")
         self.performAction("new", "rename")

test/check-machines-settings

@@ -439,6 +439,8 @@ class TestMachinesSettings(machineslib.VirtualMachinesCase):
         # Verify that unit conversions work
         b.select_from_dropdown("#vm-subVmTest1-memory-modal-memory-unit-select", "GiB")
         b.wait_attr("#vm-subVmTest1-memory-modal-memory", "value", "0")
+        b.click("#vm-memory-modal button[aria-label='Close']")
+        b.wait_not_present("#vm-memory-modal")
 
         # Run VM
         b.click("#vm-subVmTest1-system-run")