chart: drop redundant int() wrapper around cidrPrefixLen calls #166

cidrPrefixLen (engine helper in pkg/engine/helm/engine.go) returns Go int. Two chart-side callers wrap it in Sprig's int:

• charts/talm/templates/_helpers.tpl:151 — inside addresses_by_link filter
• charts/talm/templates/_helpers.tpl:564 — inside default_addresses_by_gateway filter (added in fix(charts): pin Layer2VIPConfig to subnet-matching link, not default route #163)

The third caller in the same file (link_name_for_address line 429) uses the bare form $prefixLen := cidrPrefixLen $address directly. The outer int is a no-op; dropping it brings the three call sites into one consistent style.

Reference: PR #163 review, flagged as non-blocking.