Remove some additional version guards for Ruby 3.0.x #375

Job	Run time
RuboCop	33s
specs (ubuntu, 3.1.6)	1m 39s
specs (ubuntu, 3.2.6)	1m 32s
specs (ubuntu, 3.3.7)	1m 28s
specs (ubuntu, 3.4.1)	1m 36s
specs (macos, 3.1.6)	1m 20s
specs (macos, 3.2.6)	1m 17s
specs (macos, 3.3.7)	1m 13s
specs (macos, 3.4.1)	1m 26s
specs (windows, 3.1.6)	3m 58s
specs (windows, 3.2.6)	3m 44s
specs (windows, 3.3.7)	4m 21s
specs (windows, 3.4.1)	5m 28s
specs (ubuntu, 3.3.0, --enable-frozen-string-literal)	1m 26s
	31m 1s

Provide feedback