[lldb][test][DAP] Disable TestDAP_attach.py on Arm Linux

Despite llvm#163452, this is still timing out on our Arm bot. Probably
because schedling is unpredicatable, but that's just reality so
I'm not going to fight that.

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Exit Code: -9
Timeout: Reached timeout of 600 seconds

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ERROR: test_by_name_waitFor (TestDAP_attach.TestDAP_attach)
   Tests waiting for, and attaching to a process by process name that
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Traceback (most recent call last):
  File "/home/tcwg-buildbot/worker/lldb-arm-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2066, in tearDown
    Base.tearDown(self)
  File "/home/tcwg-buildbot/worker/lldb-arm-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 1106, in tearDown
    hook()  # try the plain call and hope it works
  File "/home/tcwg-buildbot/worker/lldb-arm-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/lldbdap_testcase.py", line 499, in cleanup
    self.dap_server.request_disconnect(terminateDebuggee=True)
  File "/home/tcwg-buildbot/worker/lldb-arm-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py", line 926, in request_disconnect
    return self._send_recv(command_dict)
  File "/home/tcwg-buildbot/worker/lldb-arm-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py", line 548, in _send_recv
    raise ValueError(f"no response for {request!r}")
ValueError: no response for {'command': 'disconnect', 'type': 'request', 'arguments': {'terminateDebuggee': True}, 'seq': 3}
Config=arm-/home/tcwg-buildbot/worker/lldb-arm-ubuntu/build/bin/clang
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I don't think this is an Arm thing specifically, but it's the most
diplomatic way to stop false negatives from this test.

Author: DavidSpickett

lldb/test/API/tools/lldb-dap/attach/TestDAP_attach.py

@@ -11,6 +11,9 @@
 import time
 
 
+# Often fails on Arm Linux, but not specifically because it's Arm, something in
+# process scheduling can cause a massive (minutes) delay during this test.
+@skipIf(oslist=["linux"], archs=["arm$"])
 class TestDAP_attach(lldbdap_testcase.DAPTestCaseBase):
     def spawn(self, args):
         self.process = subprocess.Popen(