"ERROR: Path does not exist" when using trailing \ on manifest path (submit)

Start by reproducing the issue with the wingetcreate submit command using the manifest path examples in the report, then trace the submit command's path validation entry point. Done means a path with one or more trailing backslashes is accepted just like the same path without them, while nonexistent paths still report an error.

Brief description of your issue

When using "wingetcreate submit "PATH_TO_MANIFEST" and PATH_TO_MANIFEST have a trailing \, it will fail with:
"ERROR: Path does not exist".

Steps to reproduce

wingetcreate submit ".\manifests\x\XX\XXX\VERSION.NUMBERS\"
fails while
wingetcreate submit ".\manifests\x\XX\XXX\VERSION.NUMBERS"
does not fail

Expected behavior

A trailing \ should be allowed, and not cause a path error.

Actual behavior

"ERROR: Path does not exist"

Environment

Windows Package Manager Manifest Creator v1.5.7.0

Windows Package Manager (Preview) v1.7.3172-preview
Copyright (c) Microsoft Corporation. All rights reserved.

Windows: Windows.Desktop v10.0.23606.1000
System Architecture: X64
Package: Microsoft.DesktopAppInstaller v1.22.3172.0

Winget Directories
----------------------------------------------------------------------------------------------------- Logs                               %LOCALAPPDATA%\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bb… User Settings                      %LOCALAPPDATA%\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bb… Portable Links Directory (User)    %LOCALAPPDATA%\Microsoft\WinGet\Links
Portable Links Directory (Machine) C:\Program Files\WinGet\Links
Portable Package Root (User)       %LOCALAPPDATA%\Microsoft\WinGet\Packages
Portable Package Root              C:\Program Files\WinGet\Packages
Portable Package Root (x86)        C:\Program Files (x86)\WinGet\Packages
Installer Downloads                %USERPROFILE%\Downloads

Links
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Privacy Statement   https://aka.ms/winget-privacy
License Agreement   https://aka.ms/winget-license
Third Party Notices https://aka.ms/winget-3rdPartyNotice
Homepage            https://aka.ms/winget
Windows Store Terms https://www.microsoft.com/en-us/storedocs/terms-of-sale

Admin Setting                             State
--------------------------------------------------
LocalManifestFiles                        Enabled
BypassCertificatePinningForMicrosoftStore Disabled
InstallerHashOverride                     Disabled
LocalArchiveMalwareScanOverride           Disabled