fix: issue where kustomization files are empty

[a1994sc]

Description

This PR addresses a where zarf is unable to properly discover the images from a kustomization file.

The culprit from my testing seems to be cause by f and newDestination being the same values when calling helpers.CreatePathAndCopy here

	...
	if err := helpers.CreatePathAndCopy(f, newDestination); err != nil {
	...

That function, found here, basically copies a file from one path to another, however there is no check if the source and destination are same values. This causes the resulting file to be empty.

The change in my PR uses the temp folder already created by zarf to make sure that source and destination files are different, preventing an empty file from being scanned.

Related Issue

Fixes #3065

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide Steps followed

[netlify]

✅ Deploy Preview for zarf-docs canceled.

Name	Link
🔨 Latest commit	edd902c
🔍 Latest deploy log	https://app.netlify.com/sites/zarf-docs/deploys/672253074dbf710008b2fe29

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
src/pkg/packager/prepare.go	52.63% <100.00%> (+1.60%)	⬆️

[phillebaba]

@a1994sc how much effort do you think it would be to add a test for this fix?

[a1994sc]

I would have look into how the existing testing is done, so I'm unsure

[a1994sc]

@phillebaba I updated the PR with a basic unit test.