feat: improve robustness of initial install

[merll]

This PR includes the following changes for making the installation process more robust against temporary connection issues with the Kubernetes API.

• helm has been upgraded to the latest release. Since v3.15.0, it has a retry-mechanism to reattempt Kubernetes API requests on certain HTTP status codes or connection timeouts. This is currently hard-coded to 30 retries.
• helmfile and the helm-diff plugin have been upgraded for ensuring compatibility, while kubectl has been upgraded for a closer match to the supported cluster version.
• On initial install, the total amount of queries is reduced by
  • skipping validation against the OpenAPI spec of the cluster's Kubernetes API
  • bypassing helm diff and proceeding to a Helm chart install directly
  • running one helm instance at a time.
• Also on the regular pipeline, Helm has a rate limiting of 20 queries per second applied. This is most likely only to affect read queries such as CRDs.

[CasLubbers]

LGTM! ✅
Tested it: installation works and after installation I enabled all the apps in one deploy also worked.