Update Go version to 1.26.2 in devcontainer configuration

Author: chefgs

.devcontainer/devcontainer.env.json

@@ -57,7 +57,7 @@
     "python": "3.11",
     "java": "17",
     "node": "20",
-    "go": "1.21",
+    "go": "1.26.2",
     "nexus": "3.50.0",
     "prometheus": "2.45.0",
     "grafana": "10.0.0",