fix: calculate resource diff for priority as max across containers

[rudrakhp]

What type of PR is this?

/kind bug

What this PR does / why we need it:

ResourceDiff is calculated by summing all container requests per resource type and then calculating the percentage difference of these totals. This might lead to cases where even though per container diff might be high it doesn't reflect accurately in pod resource diff. In this change we take a max diff across all container-resource pairs so thresholds allow for these pods to be evicted.

Which issue(s) this PR fixes:

Fixes #8903

Special notes for your reviewer:

Does this behavior change need to be highlighted in case users are setting thresholds very low to compensate for current behavior that averages out diffs across containers? They might see more frequent evictions with this fix.

Does this PR introduce a user-facing change?

Fix resource diff calculation logic to use max diff across all container-resource pairs instead of diff percentage after summing across containers.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

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[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: rudrakhp
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