Adding Cpd540 helm changes

[nehasangwai-ibm]

Problem

Previously, the CP4D upgrade path only allowed single-hop upgrades. A customer on 5.2.0 was forced to first upgrade to 5.3.1 before upgrading to 5.4.0. There was no way to jump directly from 5.2.0 → 5.4.0.

Changes

python/src/mas/cli/update/app.py

Updated cpdUpgradePath map — changed "5.2.0" entry from a single string to a list of valid targets:

Before

"5.2.0": "5.3.1"

After

"5.2.0": ["5.3.1", "5.4.0"]

Updated validation logic — normalises the map value to a list before the check, so both str and list values are handled safely:

validNextVersions = cpdUpgradePath[cpdInstanceVersion]
if isinstance(validNextVersions, str):
    validNextVersions = [validNextVersions]

if cpdTargetVersion not in validNextVersions:
    # fatal error