Problem: gomod2nix.toml need manual adjustment (#499)

Solution:
- fix the bug in upstream: nix-community/gomod2nix#38
- update dependency
- regenerate gomod2nix.toml

flake.nix

@@ -6,7 +6,8 @@
       flake = false;
     };
     gomod2nix = {
-      url = "github:tweag/gomod2nix";
+      # https://github.com/tweag/gomod2nix/pull/38
+      url = "github:yihuang/gomod2nix/demonstrate-error";
       inputs.nixpkgs.follows = "nixpkgs";
     };
     flake-utils.url = "github:numtide/flake-utils";

gomod2nix.toml

@@ -664,15 +664,6 @@
     rev = "2f508b3f86ed9ef87bcf3426b87b6c0dc0d3632c"
     sha256 = "1hznnrl1pi5nyh6xm05wmb8knq1sm44pz4w998q01lqfpyc56z86"
 
-["github.com/btcsuite/btcd/chaincfg"]
-  sumVersion = "v1.0.1"
-  relPath = "chaincfg"
-  ["github.com/btcsuite/btcd/chaincfg".fetch]
-    type = "git"
-    url = "https://github.com/btcsuite/btcd"
-    rev = "fc36cb25a4bdc6d989f9161552e7b0fe08b02939"
-    sha256 = "0j6s4zh3bb42lihiiqmdd8wd6fvdqpa1x7hmvq2jvfpg47ng12md"
-
 ["github.com/btcsuite/btcd/chaincfg/chainhash"]
   sumVersion = "v1.0.1"
   relPath = "chaincfg/chainhash"

nix/sources.json

@@ -25,15 +25,15 @@
         "version": "hevm/0.49.0"
     },
     "gomod2nix": {
-        "branch": "master",
+        "branch": "demonstrate-error",
         "description": "Convert applications using Go modules to Nix expressions",
         "homepage": null,
-        "owner": "tweag",
+        "owner": "yihuang",
         "repo": "gomod2nix",
-        "rev": "fc5adcc53031c5a3934500a57896a840a2bd073d",
-        "sha256": "1af8sg6lfzxvhha8rbcaklihdm0q2dy4jgnjax1b4914qzfphcb6",
+        "rev": "6cdf8f60e20bfc5c58c51242bd7f329f6c5ff4b2",
+        "sha256": "0rhyfyfamgd3d97qcp1ij1rx98nd0l0ys4i48lm18a785frqj1wa",
         "type": "tarball",
-        "url": "https://github.com/tweag/gomod2nix/archive/fc5adcc53031c5a3934500a57896a840a2bd073d.tar.gz",
+        "url": "https://github.com/yihuang/gomod2nix/archive/6cdf8f60e20bfc5c58c51242bd7f329f6c5ff4b2.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "gravity-bridge": {