fix: Update Cloud Pak for Data to release 4.7.3

[nastacio]

Is your feature request related to a problem? Please describe.
Cloud Pak for Data 4.7.3 was released, so we need to update this repository.
https://www.ibm.com/docs/en/cloud-paks/cp-data/4.7.x?topic=overview-whats-new

Describe the solution you'd like
Update the CRs and jobs to reflect the updated installation procedures.

Describe alternatives you've considered
None, the requirement is pretty narrow.

Additional context
CP4D installation procedure shifted towards a procedural approach in release 4.5.x. See #173 for reference and corresponding PR with the changes to understand the nature of that change.

[nastacio]

PR validation (#283 (comment)) showing that it will not be possible to automate the deployment of CP4D 4.7.3.

[nastacio]

I also attempted another change with CP4D 4.7.4 and got the same error as in CP4D 4.7.3:

TASK [utils : Confirm existence of Catalog Source object "ibm-cpd-scheduling-catalog" in namespace "cpd-scheduler"] ***
ok: [localhost]
TASK [utils : Confirm the expect channel is found in the packagemanifest] ******
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: kubernetes.config.config_exception.ConfigException: Invalid kube-config file. No configuration found.
fatal: [localhost]: FAILED! => {"changed": false}
TASK [utils : fail] ************************************************************
fatal: [localhost]: FAILED! => {"changed": false, "msg": "Timeout of waiting for packagemanifest ibm-cpd-scheduling-operator of component ibm-cpd-scheduling-operator to be refreshed in namespace cpd-scheduler"}
PLAY RECAP *********************************************************************
localhost : ok=44 changed=9 unreachable=0 failed=1 skipped=63 rescued=1 ignored=0
+