[DOC] Doc for StringIO#gets #545

Job	Run time
ruby-versions / Generate Ruby versions	4s
ubuntu-24.04 2.7	40s
ubuntu-24.04 3.4	35s
ubuntu-24.04 3.0	25s
ubuntu-24.04 3.2	38s
ubuntu-24.04 debug	30s
ubuntu-24.04 3.3	30s
ubuntu-24.04 3.1	23s
ubuntu-24.04 head	27s
ubuntu-24.04 truffleruby-head	38s
ubuntu-22.04 2.7	34s
ubuntu-22.04 3.2	32s
ubuntu-24.04 jruby-head	1m 19s
ubuntu-22.04 3.1	29s
ubuntu-22.04 3.4	29s
ubuntu-22.04 debug	38s
ubuntu-22.04 head	23s
ubuntu-22.04 jruby-head	1m 27s
ubuntu-22.04 3.3	21s
ubuntu-22.04 3.0	23s
ubuntu-22.04 truffleruby-head	44s
	12m 9s

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