Remove deprecated `Encoding#replicate` method #5043

Job	Run time
ruby/spec on CRuby 3.0	3m 27s
build jvm	9m 3s
ruby/spec on CRuby 3.1	3m 38s
lint	17m 49s
build native	16m 10s
ruby/spec on CRuby 3.2	3m 6s
test integration	9m 47s
specs :truffle	14m 29s
fast specs	1m 34s
specs :language :core	12m 44s
specs :library :cext :security :command_line :tracepoint	9m 21s
run MRI tests on native	18m 47s
test native	3m 23s
	2h 3m 18s

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