Removed deprecated legacy windows platform support #7134

Job	Run time
Rubygems on macOS (3.4)	5m 50s
Rubygems on macOS (3.3)	1m 40s
Rubygems on Ubuntu (jruby)	7m 18s
Rubygems on Ubuntu (3.4)	4m 7s
Rubygems on Ubuntu (truffleruby)	3m 43s
Rubygems on Ubuntu (3.2)	1m 59s
Rubygems on Windows (3.2)	4m 15s
Rubygems on Windows (3.3)	4m 50s
Rubygems on macOS (3.2)	2m 23s
Rubygems on Ubuntu (3.3)	1m 59s
Rubygems on Windows (3.4)	3m 52s
All rubygems jobs pass	3s
	41m 59s

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