Update SFM checkpoint after K562 and ChIP-seq refinement

Replace the SFM weights with the selected checkpoint from the K562 Perturb-seq and hESC/mESC ChIP-seq refinement run.

models/sfm/sfm_model.safetensors

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:02c6959f30ccd584943f4dafa023732c1151615ce589abb2463878683dafa0a3
-size 541601608
+oid sha256:f4e4e3e289f66d51fe8812e28a747cc3b45d767864b44e8e1dceba12f6dfec74
+size 537446772