fix(coprocessor): bump tfhe to alpha.2

Author: antoniupop

coprocessor/fhevm-engine/Cargo.lock

@@ -68,7 +68,7 @@ sqlx = { version = "0.8.6", default-features = false, features = [
 ] }
 testcontainers = "0.24.0"
 thiserror = "2.0.12"
-tfhe = { version = "1.4.0-alpha.1", features = [
+tfhe = { version = "1.4.0-alpha.2", features = [
     "boolean",
     "shortint",
     "integer",