Derivatives from back propagation and start of work on multicolvar GPUs #3591

Job	Run time
codecheck / codecheck	45m 24s
conda / conda (ubuntu-22.04)	12m 31s
conda / conda (macos-13)	25m 25s
conda / conda (macos-14)	11m 48s
docker / docker (fedora39)	20m 22s
docker / docker (rocky8)	23m 53s
linux / linux (-doc-mpi-)	40m 55s
linux / linux (-mpi-)	51m 30s
mac / macports (macos-13)	17m 20s
linux / linux (-coverage-mpi-)	1h 0m 31s
mac / macports (+allmodules, macos-13)	21m 16s
linux / linux (-debug-)	37m 36s
linux / linux (-debug-mpi-)	50m 35s
linux / linux (-intel-)	46m 42s
linux / linux (-pycv-mpi-)	17m 45s
mac / macsimple (macos-13)	11m 26s
linux / linux (-nvhpc-mpi-)	54m 45s
mac / macsimple (macos-14)	6m 4s
	9h 15m 48s

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