ci: fix k6 version

Author: szkiba

.github/workflows/release.yml

@@ -14,7 +14,7 @@ jobs:
       contents: write
     with:
       go-version: "1.24.x"
-      k6-version: "1.0.0"
+      k6-version: "v1.0.0"
       xk6-version: "1.0.1"
       os: '["linux","windows","darwin"]'
       arch: '["amd64","arm64"]'