Add support for SLES 15 and 16

[jdreinhardt]

Issue #, if available:
N/A

Description of changes:
Added OS support for SLES 15 SP7 and SLES 16.0 (amd64 and arm64)

• Added SLES (zypper) support into nodeadm
• Added SLES tests into e2e suite
• Updated kubelet.service to use relative path for iptables instead of absolute

Testing (if applicable):

• Go unit tests for nodeadm changes
• Integration tests for all SLES OS variants
• Full e2e test against all SLES OS variants and EKS Kubernetes version (1.31-1.36)
• Regression check e2e validation against existing OS variants

Documentation added/planned (if applicable):

• EKS User Guide, Hybrid Nodes Supported OS docs

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