[Windows] Embedded python is not used by lldb/REPL

It seems the embedded python is not added to PATH (don't know if it's intentional) during installation and REPL/lldb reports python dll not found error despite the fact that embedded python has been selected and be installed.  ``` Desktop ~ $ where.exe swift C:\Users\[redacted]\AppData\Local\Programs\Swift\Toolchains\0.0.0+Asserts\usr\bin\swift.exe Desktop ~ $ swift repl warning: There is an architecture mismatch between the installed toolchain and the resolved Python's architecture: Toolchain: x64 Python: unknown error: unable to find 'python310.dll'. Welcome to Swift version 6.3-dev (LLVM 35f48306184cd25, Swift a69dbb3366e64d8). Type :help for assistance. 1> Desktop ~ $ ls C:\Users\[redacted]\AppData\Local\Programs\Swift\ Platforms/ Python-3.10.1/ Redistributables/ Runtimes/ Toolchains/ Desktop ~ $ ls C:\Users\[redacted]\AppData\Local\Programs\Swift\Python-3.10.1\python310.dll 'C:\Users\[redacted]\AppData\Local\Programs\Swift\Python-3.10.1\python310.dll'* ```