Downgrade go-ethereum to v1.16.8 across all modules

- templates: v1.17.0 -> v1.16.8
- test: v1.17.0 -> v1.16.8, removed the replace directive workaround
  since the dependency is now pinned directly

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: joshuahannan

lib/go/templates/go.mod

@@ -17,7 +17,7 @@ require (
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.2.0 // indirect
-	github.com/ethereum/go-ethereum v1.17.0 // indirect
+	github.com/ethereum/go-ethereum v1.16.8 // indirect
 	github.com/fxamacker/cbor/v2 v2.8.1-0.20250402194037-6f932b086829 // indirect
 	github.com/fxamacker/circlehash v0.3.0 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect

lib/go/templates/go.sum

@@ -11,8 +11,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/decred/dcrd/dcrec/secp256k1/v4 v4.2.0 h1:8UrgZ3GkP4i/CLijOJx79Yu+etlyjdBU4sfcs2WYQMs=
 github.com/decred/dcrd/dcrec/secp256k1/v4 v4.2.0/go.mod h1:v57UDF4pDQJcEfFUCRop3lJL149eHGSe9Jvczhzjo/0=
-github.com/ethereum/go-ethereum v1.17.0 h1:2D+1Fe23CwZ5tQoAS5DfwKFNI1HGcTwi65/kRlAVxes=
-github.com/ethereum/go-ethereum v1.17.0/go.mod h1:2W3msvdosS/MCWytpqTcqgFiRYbTH59FxDJzqah120o=
+github.com/ethereum/go-ethereum v1.16.8 h1:LLLfkZWijhR5m6yrAXbdlTeXoqontH+Ga2f9igY7law=
+github.com/ethereum/go-ethereum v1.16.8/go.mod h1:Fs6QebQbavneQTYcA39PEKv2+zIjX7rPUZ14DER46wk=
 github.com/fxamacker/cbor/v2 v2.8.1-0.20250402194037-6f932b086829 h1:qOglMkJ5YBwog/GU/NXhP9gFqxUGMuqnmCkbj65JMhk=
 github.com/fxamacker/cbor/v2 v2.8.1-0.20250402194037-6f932b086829/go.mod h1:vM4b+DJCtHn+zz7h3FFp/hDAI9WNWCsZj23V5ytsSxQ=
 github.com/fxamacker/circlehash v0.3.0 h1:XKdvTtIJV9t7DDUtsf0RIpC1OcxZtPbmgIH7ekx28WA=

lib/go/test/go.mod

@@ -51,7 +51,7 @@ require (
 	github.com/emicklei/dot v1.6.2 // indirect
 	github.com/ethereum/c-kzg-4844/v2 v2.1.5 // indirect
 	github.com/ethereum/go-bigmodexpfix v0.0.0-20250911101455-f9e208c548ab // indirect
-	github.com/ethereum/go-ethereum v1.17.0 // indirect
+	github.com/ethereum/go-ethereum v1.16.8 // indirect
 	github.com/ethereum/go-verkle v0.2.2 // indirect
 	github.com/ferranbt/fastssz v0.1.4 // indirect
 	github.com/fsnotify/fsnotify v1.6.0 // indirect
@@ -224,7 +224,3 @@ require (
 replace github.com/onflow/flow-nft/lib/go/contracts => ../contracts
 
 replace github.com/onflow/flow-nft/lib/go/templates => ../templates
-
-// ethereum/go-ethereum v1.17.0 removed trie/utils which is still imported by
-// flow-go; pin to the last version that includes it.
-replace github.com/ethereum/go-ethereum => github.com/ethereum/go-ethereum v1.16.8