[lldb][test] Skip registration-unique.test on Windows

Fails with:
```
RUN: at line 4
split-file C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Recognizer\registration-unique.test C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp
executed command: split-file 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Recognizer\registration-unique.test' 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp'
note: command had no output on stdout or stderr
RUN: at line 6
c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\clang.exe --target=specify-a-target-or-use-a-_host-substitution --target=aarch64-pc-windows-msvc -fmodules-cache-path=C:/Users/tcwg/llvm-worker/lldb-aarch64-windows/build/lldb-test-build.noindex/module-cache-clang\lldb-shell C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/main.cpp -g -o C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/cpp.out
executed command: 'c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\clang.exe' --target=specify-a-target-or-use-a-_host-substitution --target=aarch64-pc-windows-msvc '-fmodules-cache-path=C:/Users/tcwg/llvm-worker/lldb-aarch64-windows/build/lldb-test-build.noindex/module-cache-clang\lldb-shell' 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/main.cpp' -g -o 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/cpp.out'
.---command stderr------------
| clang: warning: argument unused during compilation: '-fmodules-cache-path=C:/Users/tcwg/llvm-worker/lldb-aarch64-windows/build/lldb-test-build.noindex/module-cache-clang\lldb-shell' [-Wunused-command-line-argument]
`-----------------------------
RUN: at line 7
c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\lldb.exe --no-lldbinit -S C:/Users/tcwg/llvm-worker/lldb-aarch64-windows/build/tools/lldb\test\Shell\lit-lldb-init-quiet -b -s C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/commands.input C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/cpp.out | c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\filecheck.exe C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Recognizer\registration-unique.test
executed command: 'c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\lldb.exe' --no-lldbinit -S 'C:/Users/tcwg/llvm-worker/lldb-aarch64-windows/build/tools/lldb\test\Shell\lit-lldb-init-quiet' -b -s 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/commands.input' 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Recognizer\Output\registration-unique.test.tmp/cpp.out'
note: command had no output on stdout or stderr
executed command: 'c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\filecheck.exe' 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Recognizer\registration-unique.test'
.---command stderr------------
| C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Recognizer\registration-unique.test:45:10: error: CHECK: expected string not found in input
| # CHECK: Assert StackFrame Recognizer
|          ^
| <stdin>:20:38: note: scanning from here
| 1: Verbose Trap StackFrame Recognizer, demangled symbol regex ^__clang_trap_msg
|                                      ^
| <stdin>:34:10: note: possible intended match here
| 3: Verbose Trap StackFrame Recognizer, demangled symbol regex ^__clang_trap_msg
|          ^
|
| Input file: <stdin>
| Check file: C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Recognizer\registration-unique.test
|
| -dump-input=help explains the following input dump.
```

(cherry picked from commit 8636c40)

Author: Michael137

lldb/test/Shell/Recognizer/registration-unique.test

@@ -1,3 +1,5 @@
+# UNSUPPORTED: system-windows
+
 # Checks that the recognizers that should work across language runtimes
 # are only registered once with the target.