Bump apollo-server-core from 3.11.1 to 3.12.1 #214

Job	Run time
Cancel previous runs	2s
Build and test (14.x, ubuntu-latest)	2m 48s
Build and test (14.x, windows-latest)	4m 50s
Build and test (14.x, macOS-latest)	4m 51s
Build and test (16.x, ubuntu-latest)	1m 56s
Build and test (16.x, windows-latest)	5m 7s
Build and test (16.x, macOS-latest)	5m 5s
Build and test (18.x, ubuntu-latest)	2m 10s
Build and test (18.x, windows-latest)	5m 2s
Build and test (18.x, macOS-latest)	1m 16s
coveralls	0s
	33m 7s

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