Limit beaker-puppet to older Rubies #40

Job	Run time
Released / Puppet7 gem on Ruby 2.7 on Linux	46s
Nightly / Puppet7 gem on Ruby 2.7 on Linux	1m 3s
Released / Puppet8 gem on Ruby 3.1 on Linux	29s
Nightly / Puppet8 gem on Ruby 3.1 on Linux	31s
Released / Puppet7 gem on Ruby 2.7 on macOS	1m 35s
Nightly / Puppet7 gem on Ruby 2.7 on macOS	2m 53s
Released / Puppet8 gem on Ruby 3.1 on macOS	1m 4s
Nightly / Puppet8 gem on Ruby 3.1 on macOS	1m 10s
Released / Puppet7 gem on Ruby 2.7 on Windows	4m 44s
Nightly / Puppet7 gem on Ruby 2.7 on Windows	5m 53s
Released / Puppet8 gem on Ruby 3.1 on Windows	4m 12s
Nightly / Puppet8 gem on Ruby 3.1 on Windows	3m 38s
	27m 58s

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