Update release version number for M135, 11.4.0 (#1421)

Author: AlmostMatt

cpp_sdk_version.json

@@ -1,5 +1,5 @@
 {
-  "released": "11.3.0",
-  "stable": "11.3.0",
-  "head": "11.3.0"
+  "released": "11.4.0",
+  "stable": "11.4.0",
+  "head": "11.4.0"
 }