[DOC] Tweaks for StringIO#external_encoding (#161) #547

Job	Run time
ruby-versions / Generate Ruby versions	5s
ubuntu-24.04 2.7	26s
ubuntu-24.04 3.2	21s
ubuntu-24.04 3.0	15s
ubuntu-24.04 3.1	12s
ubuntu-24.04 head	11s
ubuntu-22.04 2.7	27s
ubuntu-24.04 truffleruby-head	26s
ubuntu-22.04 3.0	12s
ubuntu-24.04 jruby-head	1m 7s
ubuntu-22.04 3.2	24s
ubuntu-24.04 3.3	22s
ubuntu-22.04 jruby-head	1m 17s
ubuntu-22.04 3.3	17s
ubuntu-22.04 head	17s
ubuntu-22.04 3.4	24s
ubuntu-24.04 3.4	20s
ubuntu-22.04 3.1	17s
ubuntu-24.04 debug	23s
ubuntu-22.04 debug	27s
ubuntu-22.04 truffleruby-head	30s
	8m 40s

Provide feedback