phlex.gemspec: Drop exe/ mentions (#604) #1530

Job	Run time
rubocop	11s
tests (ubuntu-latest, 2.7)	23s
tests (ubuntu-latest, 3.0)	8s
tests (ubuntu-latest, 3.1)	11s
tests (ubuntu-latest, 3.2)	7s
tests (ubuntu-latest, head)	7s
tests (ubuntu-latest, truffleruby-22.2)	39s
tests (ubuntu-latest, truffleruby-22.3)	38s
tests (ubuntu-latest, truffleruby-head)	30s
tests (macos-latest, 2.7)	57s
tests (macos-latest, 3.0)	18s
tests (macos-latest, 3.1)	26s
tests (macos-latest, 3.2)	21s
tests (macos-latest, head)	23s
tests (macos-latest, truffleruby-22.2)	1m 22s
tests (macos-latest, truffleruby-22.3)	1m 1s
tests (macos-latest, truffleruby-head)	40s
	8m 22s

Provide feedback