Remove `verify_signature` syscall

[Stebalien]

We now have a new verify_bls_aggregate syscall and can remove the old verify_signature syscall in the next major version.

[rjan90]

This needs to land after nv23

[Stebalien]

Specifically, this needs to land once we make the next major release of the FVM (which isn't currently planned).

[Stebalien]

Note: we also need to disable this feature in the builtin actors. Once we do that, the builtin actors will no longer be using this syscall and it can be removed entirely in the next major FVM version.

[rvagg]

oh, we should do that in builtin-actors to make FIP-0079 complete, right? that should probably go on the nv23 checklist.

[Stebalien]

Yeah, although we first need to release a new FVM version (4.3 is the safest). Then we should be able to patch the builtin-actors as follows:

diff --git a/Cargo.toml b/Cargo.toml
index e6166066..c2cca25a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -121,8 +121,8 @@ frc42_dispatch = "5.0.0"
 frc46_token = "9.0.0"
 
 # FVM
-fvm_sdk = "~4.0"
-fvm_shared = "~4.0"
+fvm_sdk = { version = "~4.3", default-features = false }
+fvm_shared = "~4.3"
 fvm_ipld_encoding = "0.4.0"
 fvm_ipld_blockstore = "0.2.0"
 fvm_ipld_hamt = "0.8.0"

[rvagg]

ok, let's wait to get the new ni-porep proofs in and then do a 4.3