init_fs_encoding fails when include_distribution_sources = False

Nobody has claimed this yet.

Hey :-) When I set `include_distribution_sources = False`, the interpreter fails to start:

```
$ pyoxidizer run --release --target-triple i686-pc-windows-msvc
[ ... ]
Python path configuration:
PYTHONHOME = 'C:\w\build\i686-pc-windows-msvc\release\install\foo'
PYTHONPATH = (not set)
program name = 'C:\w\build\i686-pc-windows-msvc\release\install\foo\foo.exe'
isolated = 1
environment = 0
user site = 0
import site = 1
sys._base_executable = 'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo\\foo.exe'
sys.base_prefix = 'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo'
sys.base_exec_prefix = 'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo'
sys.platlibdir = 'lib'
sys.executable = 'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo\\foo.exe'
sys.prefix = 'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo'
sys.exec_prefix = 'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo'
sys.path = [
'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo\\python310.zip',
'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo\\DLLs',
'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo\\lib',
'C:\\w\\build\\i686-pc-windows-msvc\\release\\install\\foo',
]
error instantiating embedded Python interpreter: during initializing Python main: init_fs_encoding: failed to get the Python codec of the filesystem encoding
error: cargo run failed
```

my `pyoxidizer.bzl` is:
```bazel
def make_exe():
dist = default_python_distribution()
policy = dist.make_python_packaging_policy()
policy.include_distribution_sources = False
python_config = dist.make_python_interpreter_config()
exe = dist.to_python_executable(
name="foo",
config=python_config,
packaging_policy=policy,
)
return exe

def make_embedded_resources(exe):
return exe.to_embedded_resources()

def make_install(exe):
files = FileManifest()
files.add_python_resource("foo", exe)
return files

register_target("exe", make_exe)
register_target("resources", make_embedded_resources, depends=["exe"], default_build_script=True)
register_target("install", make_install, depends=["exe"], default=True)
resolve_targets()
```

At first I thought it was due to some other specifics of my bzl (static build, py3.8 for win7 support, windows_runtime_dlls_mode=never) but it still happens after simplifying it to this.

My assumption was that it would compile the source modules to bytecode and include those into the exe instead; maybe I'm mistaken? Seeing the `PYTHONHOME` in the output, is the intention to provide your own copy of the stdlib, similar to the zipfile in the official cpython windows-embedded-packages?

Start with the minimal pyoxidizer.bzl configuration in the report and reproduce the failure using `pyoxidizer run --release --target-triple i686-pc-windows-msvc` with `include_distribution_sources = False`. Trace the embedded Python startup failure around `init_fs_encoding`; done means the generated executable starts successfully with that policy setting.

Written by the indexing model from the issue text.