[lldb][lldb-dap][test] Correct skip in TestDAP_launch

Fixes 4f65345

Yet again I forgot it's skip[I]f.

(cherry picked from commit 0fca1e4)

Author: DavidSpickett

lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py

@@ -432,7 +432,7 @@ def test_commands(self):
         self.verify_commands("terminateCommands", output, terminateCommands)
 
     # Flakey on 32-bit Arm Linux.
-    @skipif(oslist=["linux"], archs=["arm$"])
+    @skipIf(oslist=["linux"], archs=["arm$"])
     def test_extra_launch_commands(self):
         """
         Tests the "launchCommands" with extra launching settings