test: pepr load test (#1404)

## Description

Adds an automation script to run a (reasonably) large set of resources
through a given combination of Pepr module / package (.tgz) / image
(.tar) within an isolated k3d cluster.

Generates a series of Mem/CPU data points while running & outputs a
graph of them as a result.

## Related Issue

Relates to #1350 

## 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) - test

## Checklist before merging
- [ ] Unit,
[Journey](https://github.com/defenseunicorns/pepr/tree/main/journey),
[E2E Tests](https://github.com/defenseunicorns/pepr-excellent-examples),
[docs](https://github.com/defenseunicorns/pepr/tree/main/docs),
[adr](https://github.com/defenseunicorns/pepr/tree/main/adr) added or
updated as needed
- [ ] [Contributor Guide
Steps](https://docs.pepr.dev/main/contribute/#submitting-a-pull-request)
followed

.gitignore

@@ -23,7 +23,9 @@ stats.html
 insecure-tls*
 pepr-test-module
 pepr-upgrade-test
+*.tar
 *.tgz
+load/
 coverage/
 .DS_Store
 # Test binary, build with `go test -c`