update version (#97)

Author: critesjosh

bignum_example/circuits/Nargo.toml

@@ -5,4 +5,4 @@ authors = [""]
 compiler_version = ">=1.0.0"
 
 [dependencies]
-noir_bignum = { tag = "v0.7.3", git = "https://github.com/noir-lang/noir-bignum" }
+noir_bignum = { tag = "v0.8.0", git = "https://github.com/noir-lang/noir-bignum" }