Update `io.rbs` #3250

Job	Run time
windows (windows-2019, ucrt)	1m 26s
windows (windows-2019, mswin)	1m 9s
windows (windows-2022, ucrt)	1m 26s
windows (windows-2022, mswin)	1m 47s
test (master-nightly-focal, test)	2m 40s
test (master-nightly-focal, stdlib_test)	2m 35s
test (master-nightly-focal, rubocop validate test_doc build test_generate_stdlib)	2m 46s
test (master-nightly-focal, lexer confirm_lexer)	3m 57s
test (master-nightly-focal, lexer compile)	4m 13s
test (3.2-dev-focal, test)	2m 21s
test (3.2-dev-focal, stdlib_test)	2m 44s
test (3.2-dev-focal, rubocop validate test_doc build test_generate_stdlib)	2m 54s
test (3.2-dev-focal, lexer confirm_lexer)	4m 0s
test (3.2-dev-focal, lexer compile)	4m 0s
test (3.1-dev-focal, test)	2m 12s
test (3.1-dev-focal, rubocop validate test_doc build test_generate_stdlib)	3m 15s
test (3.1-dev-focal, lexer confirm_lexer)	4m 57s
test (3.1-dev-focal, lexer compile)	4m 6s
test (3.0-dev-focal, test)	3m 2s
test (3.0-dev-focal, rubocop validate test_doc build test_generate_stdlib)	2m 26s
test (3.0-dev-focal, lexer confirm_lexer)	4m 20s
test (3.0-dev-focal, lexer compile)	4m 25s
	1h 6m 41s

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