The WinGet task doesn't work because WithRetry is not defined

[MarkOsborneMS]

Describe the bug
When I try and run the WinGet task using the DevBox CLI I get the following error:
"stderr":"WithRetry : The term 'WithRetry' is not recognized as the name of a cmdlet, function, script file, or operable program.

To Reproduce
Steps to reproduce the behavior:

1. Attach our catalog that contains the WinGet task from the microsoft/devcenter-catalog (github.com)
2. Create a devbox.yaml that uses the WinGet task
3. Run the devbox.yaml on a dev box using the DevBox CLI
4. See error
   "stderr":"WithRetry : The term 'WithRetry' is not recognized as the name of a cmdlet, function, script file, or operable program.

Expected behavior
It works

Additional context
In Tasks/winget/main.ps1

WithRetry is used but not defined and generates the following error when I try and run a WinGet task using the DevBox CLI:

"stderr":"WithRetry : The term 'WithRetry' is not recognized as the name of a cmdlet, function, script file, or operable program.

It looks like the code was copied from the git-clone task but WithRetry function was missed.

[davidzenisu]

Just ran into the exact same issue.

[MarkOsborneMS]

Proposed fix in PR #61