Backport worker_may_ignore history handling

[d2army]

Summary

• Backport worker_may_ignore history handling from the 0.1.x line to transfers-master / 0.0.x without proto regeneration.
• Make History::Event constructable when a history event has an attributes oneof unknown to the old generated proto, so worker_may_ignore can still be read.
• Ignore known Nexus/options-updated events and unknown worker-ignorable events while preserving fail-closed behavior for non-ignorable unknown events.
• Prepare the 0.0.7 release with a version bump and changelog entry.

Why (#1)

• Temporal Cloud can attach new Nexus/options-updated history events that older 0.0.x Ruby workers do not understand.
• On the 0.0.x line, History::Event#extract_attributes can receive nil for an unknown attributes oneof and raise before worker_may_ignore is read; making attribute extraction nil-safe keeps the compatibility bit reachable.

Why (#2)

• StateManager#apply_event calls History::EventTarget.from_event(event) before its event-type case statement, so unknown event prefixes can raise before the final unsupported-event branch is reached.
• This backport adds the upstream ignore paths for known safe event types and for unknown events marked worker_may_ignore=true, while still raising for unknown events that are not explicitly safe to ignore.

Test plan

• RBENV_VERSION=3.0.6 bundle exec rspec -r temporal/connection/grpc spec/unit/lib/temporal/workflow/history/event_spec.rb spec/unit/lib/temporal/workflow/state_manager_spec.rb
• RBENV_VERSION=3.0.6 ruby -c lib/temporal/version.rb && RBENV_VERSION=3.0.6 ruby -c spec/unit/lib/temporal/workflow/history/event_spec.rb && git diff --check

Follow-up validation

• Replay-history fixture coverage is intentionally deferred; this PR keeps the hotfix backport focused on unit coverage for the new state-manager paths plus a cross-schema protobuf decode case.
• Before server-side rollout, Coinbase consumers should validate 0.0.7 with a bundle update and worker/workflow smoke tests.