Remove deprecated `Encoding#replicate` method #5047

Job	Run time
ruby/spec on CRuby 3.0	3m 29s
lint	14m 56s
ruby/spec on CRuby 3.1	3m 35s
build jvm	9m 5s
build native	16m 35s
ruby/spec on CRuby 3.2	3m 18s
fast specs	1m 37s
test integration	9m 37s
specs :truffle	14m 59s
specs :language :core	12m 29s
specs :library :cext :security :command_line :tracepoint	9m 28s
run MRI tests on native	19m 36s
test native	3m 11s
	2h 1m 55s

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