chore: bump client/v2 to go.mod 1.21 (#17454)

Co-authored-by: Marko <marko@baricevic.me>

Author: julienrbrt

.github/workflows/test.yml

@@ -260,7 +260,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4
         with:
-          go-version: "1.20"
+          go-version: "1.21"
           check-latest: true
           cache: true
           cache-dependency-path: client/v2/go.sum

client/v2/go.mod

@@ -1,6 +1,6 @@
 module cosmossdk.io/client/v2
 
-go 1.20
+go 1.21
 
 require (
 	cosmossdk.io/api v0.7.0