[lldb] Temporarily disable TestSymbolFileJSON on non Darwin platforms

The new test is triggering a crash in LLDB on the Windows and Linux
bots. Temporarily disable the test while I investigate.

(cherry picked from commit 15653dc)

Author: JDevlieghere

lldb/test/API/macosx/symbols/TestSymbolFileJSON.py

@@ -12,6 +12,7 @@ def setUp(self):
         self.source = 'main.c'
 
     @no_debug_info_test
+    @skipUnlessDarwin
     def test_symbol_file_json_address(self):
         """Test that 'target symbols add' can load the symbols from a JSON file using file addresses."""