Update Helm to 2.12.2 to address Helm client vulnerability

What does this MR do?

Updates Helm client from 2.11.0 to 2.12.2 to address a helm client vulnerability.

Helm Tiller is also updated to keep simple and consistent with the Helm client version.

What are the relevant issue numbers?

Closes #56417 (closed)

cf. previous update was on !22693 (merged)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [n/a] Documentation created/updated via this MR
• Tests added for this feature/bug
• [n/a] Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• [n/a] Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer