docs: update multi-arch version to v2.9.2 in README.md

[CatherineF-dev]

What this PR does / why we need it:

How does this change affect the cardinality of KSM: (increases, decreases or does not change cardinality)

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

[k8s-ci-robot]

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[mrueg]

Can you prefix your commit message with docs: to make CI pass? Thanks!

[CatherineF-dev]

/retest

[mrueg]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CatherineF-dev, mrueg

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