[lldb][test] Skip Objective-C FrameFormat tests on Windows

This were failing on Windows CI with errors like:
```
22: (lldb) bt
23: * thread #1, stop reason = breakpoint 1.1
24:  frame #0: 0x00007ff7c5e41000 TestFrameFormatFunctionFormattedArgumentsObjC.test.tmp.objc.out`func at main.m:2
25:  frame #1: 0x00007ff7c5e4101c TestFrameFormatFunctionFormattedArgumentsObjC.test.tmp.objc.out`bar + 12 at main.m:3
26:  frame #2: 0x00007ff7c5e4103c TestFrameFormatFunctionFormattedArgumentsObjC.test.tmp.objc.out`main + 16 at main.m:5
27:  custom-frame '()'
     !~~~~~~~~~~~       error: no match expected
28:  custom-frame '(__formal=<unavailable>)'
```

Author: Michael137

lldb/test/Shell/Settings/TestCxxFrameFormatMixedLanguages.test

@@ -1,3 +1,5 @@
+# UNSUPPORTED: system-windows
+
 # Test the plugin.cplusplus.display.function-name-format setting
 # when interoperating multiple languages.
 

lldb/test/Shell/Settings/TestCxxFrameFormatObjC.test

@@ -1,3 +1,5 @@
+# UNSUPPORTED: system-windows
+
 # Test the plugin.cplusplus.display.function-name-format setting.
 
 # RUN: split-file %s %t

lldb/test/Shell/Settings/TestFrameFormatFunctionFormattedArgumentsObjC.test

@@ -1,3 +1,5 @@
+# UNSUPPORTED: system-windows
+
 # Check that we have an appropriate fallback for ${function.formatted-arguments} in languages that
 # don't implement this frame format variable (in this case Objective-C).
 #