VEM TDDFT optimizations fail after the first gradient

[edoapra]

Describe the bug
VEM TDDFT optimizations all fail after the first gradient https://groups.google.com/g/nwchem-forum/c/E0iK63zBbSA since hnd_coschg tries to use g_vem(3) that was destroyed in the tddft_gradient

To Reproduce
Input for reproducer

geometry
 c                     0.00000000     0.00000000     0.00000000
 h1                    0.62442915     0.62442915     0.62442915
 h1                   -0.62442915    -0.62442915     0.62442915
 h                    -0.62442915     0.62442915    -0.62442915
 h                     0.62442915    -0.62442915    -0.62442915
end

BASIS spherical
 * library 6-31G
END

dft
 xc xpbe96 cpbe96
end

cosmo
 do_cosmo_vem 1
 solvent dmso
end
driver
maxiter 20
end

tddft
 nroots 1
 algorithm 1
 notriplet
 target 1
 civecs
 grad
   root 1
 end
end
task tddft optimize