Update to metatensor-torch v0.7.x (#1235) #20

Job	Run time
docker / docker (fedora39)	20m 30s
conda / conda (ubuntu-22.04)	12m 28s
linux / linux (-doc-mpi-)	42m 35s
docker / docker (rocky8)	23m 28s
conda / conda (macos-13)	21m 17s
codecheck / codecheck	42m 33s
linux / linux (-mpi-)	51m 49s
conda / conda (macos-14)	7m 31s
linux / linux (-coverage-mpi-)	1h 0m 43s
mac / macports (macos-13)	24m 40s
mac / macsimple (macos-13)	9m 52s
mac / macports (+allmodules, macos-13)	33m 9s
mac / macsimple (macos-14)	4m 9s
linux / linux (-debug-)	29m 56s
linux / linux (-debug-mpi-)	41m 42s
linux / linux (-intel-)	46m 2s
linux / linux (-pycv-mpi-)	19m 7s
linux / linux (-nvhpc-mpi-)	52m 38s
	9h 4m 9s

Provide feedback