Remove Ruby 2.6 patches #278

Job	Run time
Determine necessary jobs	25s
Check whether workflow is up-to-date	2s
Install gem bundle	20s
Build Docker image [debian-10]	0s
Build Docker image [debian-11]	0s
Build Docker image [centos-8]	0s
Build Docker image [debian-12]	0s
Build Docker image [el-9]	0s
Build Docker image [ubuntu-20.04]	0s
Build Docker image [ubuntu-22.04]	0s
Build Docker image [utility]	0s
Download Ruby source [3.2.2]	12s
Download Ruby source [3.3.0]	9s
Download Rbenv source	12s
Download Ruby source [3.0.6]	19s
Download Ruby source [3.1.4]	18s
Build common DEB	29s
Build common RPM	31s
Check whether any version numbers need to be changed	40s
Build Rbenv DEB	34s
Build Rbenv RPM	28s
Finalize	1m 3s
	5m 42s

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