Bump AWF Firewall to v0.27.26

[lpcox]

Summary

Bump the AWF Firewall from v0.27.22 to v0.27.26.

Changes needed

Update pkg/constants/version_constants.go:

const DefaultFirewallVersion Version = "v0.27.26"

Checklist

• Update DefaultFirewallVersion in pkg/constants/version_constants.go
• Run make recompile to update lock files referencing the firewall image
• Verify smoke tests pass with new version
• Check release notes for breaking changes requiring codemod or config updates

Release notes

https://github.com/github/gh-aw-firewall/releases/tag/v0.27.26