Migrate to range-over-func style iteration in libcalicio-go/lib/set

[fasaxc]

Description

Modernise libcalicio-go's set type with range-over-func iterators and migrate the codebase to use them.

Related issues/PRs

Todos

• Tests
• Documentation
• Release note

Release Note

TBD

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[Copilot]

Pull request overview

This PR migrates the set iteration mechanism in libcalico-go/lib/set from callback-based Iter() to Go's modern range-over-func style using a new All() method that returns iter.Seq[T]. This modernizes the codebase to use idiomatic Go 1.23+ iteration patterns while maintaining backward compatibility by keeping the existing Iter() method.

Key changes include:

• Adding All() iter.Seq[T] method to the Set[T] interface and all implementations (Typed, Adaptive, Empty)
• Migrating all internal and external usage from s.Iter(func(item T) error {...}) to for item := range s.All() {...}
• Converting StopIteration error returns to break statements and RemoveItem returns to explicit s.Discard(item) calls
• Adding comprehensive test coverage for the new iterator including early termination, deletion during iteration, and concurrent modification scenarios

Reviewed changes

Copilot reviewed 64 out of 64 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
libcalico-go/lib/set/interface.go	Adds All() iter.Seq[T] method to Set interface
libcalico-go/lib/set/set.go	Implements All() for Typed set, updates internal methods to use new iteration
libcalico-go/lib/set/adaptive.go	Implements All() for Adaptive set with snapshot-based iteration for array-backed sets
libcalico-go/lib/set/union.go	Migrates union iteration to use All() with proper early termination handling
libcalico-go/lib/set/diff.go	Migrates difference iteration to use All() with error handling preserved
libcalico-go/lib/set/set_test.go	Adds comprehensive tests for All() method behavior
libcalico-go/lib/set/adaptive_test.go	Adds tests for Adaptive set's All() implementation
libcalico-go/lib/backend/syncersv1/dedupebuffer/dedupe_buffer.go	Migrates deduplication buffer to use range-over-func iteration
hack/cmd/deps/deps.go	Updates dependency calculation to use new iteration style
goldmane/pkg/storage/*.go	Migrates goldmane storage layer to use range-over-func iteration
felix/**/*.go	Comprehensive migration of Felix components (wireguard, route tables, nftables, iptables, BPF, dataplane, etc.)
calicoctl/calicoctl/commands/**/*.go	Migrates calicoctl command implementations to new iteration style