fix(optim): self-graft correctly

fix(optim): use weight decay cls in optimizeroptimizer

fix(optim): add missing variable in `Graft`

fix(optim/decay): inplace op

fix(optim): correct interface to _inner

fix(setup): bump

feat(functional): improve grad accum, fix einsum backwd, allow full p…

…atching

Merge branch 'functional'

Merge pull request #2 from ClashLuke/functional

Functional

feat: add backpack backend