Addons installed by helm are prone to external services errors during installation

[pmalek]

Problem statement

Whenever addons that utilize helm for installation (kong and kuma) they are prone to failure due to hosting services that host the helm charts.

Exemplar failure:

=== FAIL: test/integration  (0.00s)
INFO: setting up test environment
INFO: configuring cluster for testing environment
INFO: no existing cluster found, deploying using Kubernetes In Docker (KIND)
INFO: build a new KIND cluster with version 1.25.3
INFO: building test environment
WARNING: failure occurred, performing test cleanup
Error: tests failed: failed to deploy addon kong: Error: INSTALLATION FAILED: failed to fetch https://github.com/Kong/charts/releases/download/kong-2.13.1/kong-2.13.1.tgz : 503 Service Unavailable

https://github.com/Kong/kubernetes-ingress-controller/actions/runs/3691517677/jobs/6249752001#step:6:48

This causes the tests to fail.

Proposed solution

Introduce a (configurable?) retry mechanism which will retry whenever an error like this is received during helm chart installation.

Acceptance criteria

• as a user I can use helm based addons without worrying about intermittent network failures

[mflendrich]

@pmalek please fill in the AC, thx