chore: bump Go to v1.21 (#7)

Author: stainless-app[bot]

.github/workflows/ci.yml

@@ -19,6 +19,8 @@ jobs:
 
       - name: Setup go
         uses: actions/setup-go@v5
+        with:
+          go-version-file: ./go.mod
 
       - name: Run lints
         run: ./scripts/lint
@@ -32,6 +34,8 @@ jobs:
 
       - name: Setup go
         uses: actions/setup-go@v5
+        with:
+          go-version-file: ./go.mod
 
       - name: Bootstrap
         run: ./scripts/bootstrap

go.mod

@@ -1,6 +1,6 @@
 module github.com/anthropics/anthropic-sdk-go
 
-go 1.19
+go 1.21
 
 require (
 	cloud.google.com/go/auth v0.7.2 // indirect