Add a prune statement to the flux repository test (#1967)

## Description

This adds the new prune command to the flux test as well to reduce disk
pressure.

## Related Issue

Fixes #N/A

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [X] Other (security config, docs update, etc)

## Checklist before merging

- [X] Test, docs, adr added or updated as needed
- [X] [Contributor Guide
Steps](https://github.com/defenseunicorns/zarf/blob/main/CONTRIBUTING.md#developer-workflow)
followed

src/test/e2e/22_git_and_flux_test.go

@@ -111,4 +111,8 @@ func waitFluxPodInfoDeployment(t *testing.T) {
 	// Remove the flux example when deployment completes
 	stdOut, stdErr, err = e2e.Zarf("package", "remove", "podinfo-flux", "--confirm")
 	require.NoError(t, err, stdOut, stdErr)
+
+	// Prune the flux images to reduce disk pressure
+	stdOut, stdErr, err = e2e.Zarf("tools", "registry", "prune", "--confirm")
+	require.NoError(t, err, stdOut, stdErr)
 }