refactor: INLA::inla.mesh.2d is deprecated

[Andrea-Havron]

update using fmesher::fm_mesh_2d_inla()

[Andrea-Havron]

Can INLA::spde be updated to fmesher::fm_fem(mesh, order = 2, ...)? If so, it might be possible to switch dependency from INLA to fmesher.

• [x] Test:

  spde <- fmesher::fm_fem(mesh, order = 2)
  M0 <- spde$c0
  M1 <- spde$g1
  M2 <- spde$g2

with

spde <- INLA::inla.spde2.matern(mesh)
M0 <- spde$param.inla$M0
M1 <- spde$param.inla$M1
M2 <- spde$param.inla$M2

INLA dependent functions:

• [x] INLA::inla.nonconvex.hull, use fmesher::fm_nonconvex_hull(Loc)
• [x] INLA::inla.mesh.create, use fmesher::fm_rcdt_2d(Loc)
• [x] INLA::inla.mesh.2d, use fmesher::fm_mesh_2d(Loc)
• [x] INLA::inla.spde2.matern, fmesher::fm_fem(mesh)
• [x] INLA::inla.spde.make.A, fmesher::fm_basis(mesh, Loc)

https://inlabru-org.github.io/fmesher/articles/inla_conversion.html

[Andrea-Havron]

also refactor all GHA to remove INLA install dependency. Can I just update GHA back to using nmfs-fish-tools/ghactions4r?

[Andrea-Havron]

• [x] search and replace for spde$param.inla