Update `io.rbs` #3320

Job	Run time
windows (windows-2019, ucrt)	1m 15s
windows (windows-2019, mswin)	1m 17s
windows (windows-2022, ucrt)	1m 35s
windows (windows-2022, mswin)	1m 7s
test (master-nightly-focal, test)	2m 34s
test (master-nightly-focal, stdlib_test)	2m 7s
test (master-nightly-focal, rubocop validate test_doc build test_generate_stdlib)	2m 49s
test (master-nightly-focal, lexer confirm_lexer)	4m 1s
test (master-nightly-focal, lexer compile)	4m 0s
test (3.2-dev-focal, test)	2m 23s
test (3.2-dev-focal, stdlib_test)	2m 13s
test (3.2-dev-focal, rubocop validate test_doc build test_generate_stdlib)	2m 36s
test (3.2-dev-focal, lexer confirm_lexer)	3m 57s
test (3.2-dev-focal, lexer compile)	4m 40s
test (3.1-dev-focal, test)	2m 39s
test (3.1-dev-focal, rubocop validate test_doc build test_generate_stdlib)	2m 43s
test (3.1-dev-focal, lexer confirm_lexer)	3m 57s
test (3.1-dev-focal, lexer compile)	5m 8s
test (3.0-dev-focal, test)	2m 36s
test (3.0-dev-focal, rubocop validate test_doc build test_generate_stdlib)	2m 21s
test (3.0-dev-focal, lexer confirm_lexer)	3m 59s
test (3.0-dev-focal, lexer compile)	5m 5s
	1h 5m 2s

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