fix: make win32's drang_fs_get_cwd only fail with ENOMEM when the buffer is not null, and correctly exclude the null terminator when the buffer size is too small

Source/DrangPlatform/Source/win32/fs/dir.c

@@ -132,10 +132,10 @@ int drang_fs_get_cwd(char *buffer, size_t size, size_t *out_size)
     }
 
     if (out_size) {
-        *out_size = length;
+        *out_size = length > size ? length - 1 : length; // Exclude null terminator if the buffer is too small
     }
 
-    DRANG_CHECK(length < size, DRANG_ENOMEM);
+    DRANG_CHECK(buffer != NULL && length < size, DRANG_ENOMEM);
 
     DRANG_END_TRY_IGNORE()
 }