doc: update flux apiVersion for BB 1.33+

Please check if the MR fulfills these requirements

• The commit message follows our guidelines [https://www.conventionalcommits.org/en/v1.0.0-beta.3/#specification]
• Docs updated

What kind of change does this MR introduce? (Bug fix, feature, testing capability, docs update, ...)

Updates flux apiVersion from v1beta1 to v1beta2 per BB 1.33 release notes: https://repo1.dso.mil/platform-one/big-bang/bigbang/-/releases/1.33.0 in doc deployment examples .

Does this MR introduce a breaking change? (What changes might users need to make in their application due to this MR?)

No, but for future deployments flux CLI should be updated. Previous flux versions will no longer be supported

Prerequisites:

None, but if you want to deploy Big Bang 1.33+, then your deployment scripts/manifests should use the later version

MR Testing Instruction:

If deploying, deploy Kiam with BB 1.33+ and verify it still flux reconciles and works

JIRA Link

https://jira.il4.dso.mil/browse/P1CYBER-2526

Other information: