fix(ci): change ECR image to docker.io image (#2353)

## Description

This fixes a test flake we see where we get TOOMANYREQUESTS on ECR pulls
during CI runs on occasion. Example:
https://github.com/defenseunicorns/zarf/actions/runs/8135568196/job/22230376242?pr=2292

## Type of change

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

## Checklist before merging

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

examples/argocd/baseline/values.yaml

@@ -14,3 +14,7 @@ configs:
       url: https://github.com/stefanprodan/podinfo.git
       username: ""
       password: ""
+
+redis:
+  image:
+    repository: docker.io/library/redis

examples/argocd/zarf.yaml

@@ -15,7 +15,7 @@ components:
         valuesFiles:
           - baseline/values.yaml
     images:
-      - public.ecr.aws/docker/library/redis:7.0.15-alpine
+      - docker.io/library/redis:7.0.15-alpine
       - quay.io/argoproj/argocd:v2.9.6
       # Cosign artifacts for images - argocd - argocd-helm-chart
       - quay.io/argoproj/argocd:sha256-2dafd800fb617ba5b16ae429e388ca140f66f88171463d23d158b372bb2fae08.sig