[VC-45349] Rename cyberark-disco-agent to disco-agent across repo

[wallrj-cyberark]

Follow up to: #725

During a discussion with Atanas yesterday we've decided to rename the Cyberark Discovery and Context chart to disco-agent. Why? To avoid stutter in the namespace / name (cyberark/disco-agent) and in anticipation of a CyberArk name change.

• Rename Helm chart directory and files to deploy/charts/disco-agent
• Update image and chart repository names in makefiles and release docs
• Adjust test scripts, telemetry identifier, and selection labels
• Regenerate docs/schema and update snapshots for new chart name
• Users must pull quay.io/jetstack/disco-agent and charts/disco-agent

BREAKING CHANGE: image and Helm chart renamed from cyberark-disco-agent
to disco-agent; update any scripts, manifests, and references.

Fixes: https://venafi.atlassian.net/browse/VC-45349

Testing

Test release:

Created two new repos for disco-agent and granted permission to the robot account that is stored in a secret in this GitHub repo. When this PR is merged I'll delete the two repos for cyberark-disco-agent:

Published a new alpha tag to the repo, to trigger the release workflow:

export VERSION=v1.7.0-alpha.2
git tag --annotate --message="Release ${VERSION}" "${VERSION}"
git push origin "${VERSION}"

• https://github.com/jetstack/jetstack-secure/actions/runs/17982505933
• https://github.com/jetstack/jetstack-secure/releases/tag/v1.7.0-alpha.2

$ helm inspect chart oci://quay.io/jetstack/charts/disco-agent --devel
Pulled: quay.io/jetstack/charts/disco-agent:1.7.0-alpha.2
Digest: sha256:7fec8e163bca52434b3991ecb3b55b04875edeffd53435fca865bb3b513b2491
annotations:
  artifacthub.io/prerelease: "true"
apiVersion: v2
appVersion: v1.7.0-alpha.2
description: The disco-agent connects your Kubernetes or Openshift cluster to CyberArk
  Discovery and Context.
maintainers:
- email: support@cyberark.com
  name: CyberArk
  url: https://cyberark.com
name: disco-agent
sources:
- https://github.com/jetstack/jetstack-secure
version: v1.7.0-alpha.2

$ crane ls --omit-digest-tags quay.io/jetstack/disco-agent
v1.7.0-alpha.2

E2E test

The E2E test succeeded:

$ make ark-test-e2e
...
{"ts":1758728740142.7078,"caller":"agent/run.go:417","msg":"Data sent successfully","v":0,"logger":"Run.gatherAndOutputData.postData"}
process_cpu_seconds_total 0.4
process_max_fds 1.073741816e+09
process_network_receive_bytes_total 327779
process_network_transmit_bytes_total 227059
process_open_fds 13
process_resident_memory_bytes 4.9549312e+07
process_start_time_seconds 1.75872872528e+09
process_virtual_memory_bytes 1.300508672e+09
process_virtual_memory_max_bytes 1.8446744073709552e+19
/ko-app/ark agent -c /etc/disco-agent/config.yaml --machine-hub --logging-format=json --enable-metrics --enable-pprof