Remove "gemspec" from Gemfile #1086

Job	Run time
openssl-1.0.2u	2m 24s
openssl-1.1.0l	1m 29s
openssl-1.1.1w	1m 49s
openssl-3.0.13	2m 43s
openssl-3.1.5	2m 47s
openssl-3.2.1	3m 10s
openssl-3.3.0	3m 14s
libressl-3.1.5	2m 6s
libressl-3.2.7	2m 11s
libressl-3.3.6	2m 16s
libressl-3.4.3	2m 15s
libressl-3.5.3	2m 13s
libressl-3.6.3	2m 13s
libressl-3.7.3	2m 17s
libressl-3.8.4	2m 11s
libressl-3.9.1	2m 6s
ruby-versions / Generate Ruby versions	2s
ubuntu-22.04 2.6	1m 0s
ubuntu-22.04 2.7	56s
ubuntu-22.04 3.0	54s
ubuntu-22.04 3.1	56s
ubuntu-22.04 3.2	56s
ubuntu-22.04 3.3	49s
ubuntu-22.04 head	52s
ubuntu-22.04 truffleruby	1m 13s
ubuntu-22.04 truffleruby-head	1m 18s
ubuntu-20.04 2.6	56s
ubuntu-20.04 2.7	53s
ubuntu-20.04 3.0	51s
ubuntu-20.04 3.1	53s
ubuntu-20.04 3.2	48s
ubuntu-20.04 3.3	46s
ubuntu-20.04 head	49s
ubuntu-20.04 truffleruby-head	1m 21s
macos-latest 2.6	59s
macos-latest 2.7	50s
macos-latest 3.0	36s
macos-latest 3.1	1m 34s
macos-latest 3.2	1m 20s
macos-latest 3.3	1m 16s
macos-latest head	39s
macos-latest truffleruby-head	1m 4s
windows-latest 2.6	6m 49s
windows-latest 2.7	6m 38s
windows-latest 3.0	4m 28s
windows-latest 3.1	4m 47s
windows-latest 3.2	5m 25s
windows-latest 3.3	5m 28s
windows-latest ucrt	4m 32s
windows-latest mswin	3m 1s
	1h 43m 3s

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