feat: enable coverage linter for functional tests #1314

Job	Run time
Build Image	24s
Build Dependencies (arm-linux, arm-linux-gnueabihf)	1m 4s
Build Dependencies (linux64, x86_64-pc-linux-gnu)	1m 14s
Build (arm-linux, arm-linux-gnueabihf, arm-linux)	4m 19s
Build (linux64, x86_64-pc-linux-gnu, linux64)	3m 15s
Build (linux64_tsan, x86_64-pc-linux-gnu, linux64)	3m 27s
Build (linux64_ubsan, x86_64-pc-linux-gnu, linux64)	3m 35s
Build (linux64_fuzz, x86_64-pc-linux-gnu, linux64)	15m 1s
Build (linux64_cxx20, x86_64-pc-linux-gnu, linux64)	3m 6s
Build (linux64_sqlite, x86_64-pc-linux-gnu, linux64)	2m 58s
Build (linux64_nowallet, x86_64-pc-linux-gnu, linux64)	3m 15s
	41m 38s

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