VSCode: Add launch entry to attach to running target. #381

Job	Run time
ubuntu-20.04, gcc 7-2017-q4, cmake 3.6.0	1m 2s
ubuntu-20.04, gcc 7-2017-q4, cmake latest	1m 27s
ubuntu-20.04, gcc latest, cmake 3.6.0	1m 42s
ubuntu-20.04, gcc latest, cmake latest	1m 52s
macos-11, gcc 7-2017-q4, cmake 3.6.0	2m 16s
macos-11, gcc 7-2017-q4, cmake latest	51s
macos-11, gcc latest, cmake 3.6.0	2m 0s
macos-11, gcc latest, cmake latest	58s
windows-2019, gcc 7-2017-q4, cmake 3.6.0	3m 10s
windows-2019, gcc 7-2017-q4, cmake latest	2m 55s
windows-2019, gcc latest, cmake 3.6.0	3m 5s
windows-2019, gcc latest, cmake latest	3m 30s
	24m 48s

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