Enable RuboCop redundancy rules

[kpumuk]

Enable Lint/RedundantStringCoercion and the safe Style/Redundant* cops for assignments, exceptions, freezing, interpolation, parentheses, explicit self, and string escapes.

The autocorrections remove unnecessary intermediate assignments, coercions, receivers, grouping, and escaping while preserving behavior across the Ruby library, specs, integration tests, and tutorial code.

Style/RedundantBegin and Style/RedundantReturn remain separate follow-up changes. Style/RedundantPercentQ is intentionally not enabled.

This follows the merged ambiguity PR #3725; its diff contains only the general redundancy layer.

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[Copilot]

Pull request overview

Enables additional RuboCop redundancy cops for the Ruby codebase and applies the corresponding auto-corrections across library code, specs, integration tests, and tutorial examples to remove redundant coercions, receivers, parentheses, and escaping while preserving behavior.

Changes:

• Enable Lint/RedundantStringCoercion and several safe Style/Redundant* cops in lib/rb/.rubocop.yml.
• Replace redundant string interpolation / explicit .to_s calls with direct interpolation or .to_s where appropriate.
• Simplify Ruby expressions (redundant parentheses, redundant self, redundant intermediate assignments) across Ruby transports, protocols, structs, servers, and tests.

Reviewed changes

Copilot reviewed 30 out of 30 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tutorial/rb/RubyServer.rb	Removes redundant string interpolation by using to_s directly.
test/rb/integration/TestServer.rb	Removes redundant .to_s in interpolation for startup logging.
test/rb/core/protocol/test_json_protocol.rb	Replaces redundant "#{...}" coercions with .to_s in assertions.
test/rb/core/protocol/test_compact_protocol.rb	Replaces redundant "#{...}" coercions with .to_s in assertions.
test/rb/core/protocol/test_binary_protocol.rb	Replaces redundant "#{...}" coercions with .to_s in assertions.
lib/rb/spec/json_protocol_spec.rb	Removes redundant parentheses and redundant string escaping in expectations.
lib/rb/spec/compact_protocol_spec.rb	Removes redundant .to_s in interpolation for generated method names.
lib/rb/spec/base_transport_spec.rb	Removes redundant .freeze on literals under frozen_string_literal: true.
lib/rb/lib/thrift/union.rb	Removes redundant explicit receiver and redundant exception class in raise.
lib/rb/lib/thrift/transport/ssl_socket.rb	Removes redundant .to_s inside to_s interpolation.
lib/rb/lib/thrift/transport/ssl_server_socket.rb	Removes redundant .to_s inside to_s interpolation.
lib/rb/lib/thrift/transport/socket.rb	Removes redundant parentheses in conditional.
lib/rb/lib/thrift/transport/io_stream_transport.rb	Removes redundant .to_s calls in to_s.
lib/rb/lib/thrift/transport/http_client_transport.rb	Removes redundant to_s calls in interpolated error messages.
lib/rb/lib/thrift/transport/header_transport.rb	Removes redundant .to_s in to_s.
lib/rb/lib/thrift/transport/framed_transport.rb	Removes redundant .to_s in to_s.
lib/rb/lib/thrift/transport/buffered_transport.rb	Removes redundant .to_s in to_s.
lib/rb/lib/thrift/struct.rb	Removes redundant self. receiver for send/instance_variable_get.
lib/rb/lib/thrift/struct_union.rb	Removes redundant parentheses in a compound conditional.
lib/rb/lib/thrift/server/threaded_server.rb	Removes redundant .to_s in to_s.
lib/rb/lib/thrift/server/thread_pool_server.rb	Removes redundant .to_s in to_s.
lib/rb/lib/thrift/server/simple_server.rb	Removes redundant .to_s in to_s.
lib/rb/lib/thrift/server/base_server.rb	Removes redundant .to_s calls in nested to_s composition.
lib/rb/lib/thrift/protocol/json_protocol.rb	Removes redundant parentheses/escapes and simplifies control flow for redundancy cops.
lib/rb/lib/thrift/protocol/header_protocol.rb	Removes redundant .to_s in to_s.
lib/rb/lib/thrift/protocol/compact_protocol.rb	Removes redundant intermediate assignment/return and redundant .to_s in to_s.
lib/rb/lib/thrift/protocol/binary_protocol.rb	Removes redundant intermediate assignment/return and redundant .to_s in to_s.
lib/rb/lib/thrift/protocol/base_protocol.rb	Removes redundant string interpolation wrapper in to_s.
lib/rb/lib/thrift/bytes.rb	Removes redundant parentheses in a conditional.
lib/rb/.rubocop.yml	Enables redundancy-related RuboCop cops used to drive these auto-corrections.

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[Copilot]

Pull request overview

Copilot reviewed 30 out of 30 changed files in this pull request and generated no new comments.