Enable CyberArk E2E and integration tests in CI

[wallrj-cyberark]

Enable "ARK" tests in CI; those are tests which connect to real CyberArk Disco
APIs. This will reduce the risk of us releasing a broken the disco-agent chart.

Additionally, use a real UID in integration tests to satisfy real API validation
And add a cluster name, a shorter upload period, and a sample secret so that
it's easier to find the uploaded Secret in the UI.

Testing

The integration tests ran and succeeded, but with one failure due to a slow API response, so perhaps running these new tests for every PR commit, is going to cause frustration:

• 🟢 https://github.com/jetstack/jetstack-secure/actions/runs/21282184451/job/61254573436
• 🔴 https://github.com/jetstack/jetstack-secure/actions/runs/21283482710/job/61258874930

✖  internal/cyberark (1m1.162s) (coverage: 81.0% of statements)

=== Failed
=== FAIL: internal/cyberark TestCyberArkClient_PutSnapshot_RealAPI (61.09s)
    identity.go:293: I0123 10:47:28.571618] made successful request to StartAuthentication source="Identity.doStartAuthentication" summary="NewPackage"
    client_test.go:73: 
        	Error Trace:	/home/runner/work/jetstack-secure/jetstack-secure/internal/cyberark/client_test.go:73
        	Error:      	Received unexpected error:
        	            	failed to perform HTTP request to advance authentication: Post "https://anb5751.id.integration-cyberark.cloud/Security/AdvanceAuthentication": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
        	Test:       	TestCyberArkClient_PutSnapshot_RealAPI

DONE 277 tests, 1 failure in 62.750s
make: *** [make/test-unit.mk:5: test-unit] Error 1
Error: Process completed with exit code 2.

The E2E CI job ran and succeeded:

• 🟢 https://github.com/jetstack/jetstack-secure/actions/runs/21282184451/job/61254573455
• 🟢 https://github.com/jetstack/jetstack-secure/actions/runs/21283482710/job/61258874915

Here's a screenshot of the uploaded secrets

[wallrj-cyberark]

Copilot review: https://gist.github.com/wallrj-cyberark/956a1ea5a0eab3d97d5aab3b9687141a#104409-copilotgpt-5-mini