tools: update inspector_protocol to 9b4a4aa

PR-URL: #51293
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: cola119

tools/inspector_protocol/lib/Allocator_h.template

@@ -11,8 +11,6 @@
 namespace {{namespace}} {
 {% endfor %}
 
-enum NotNullTagEnum { NotNullLiteral };
-
 #define PROTOCOL_DISALLOW_COPY(ClassName) \
     private: \
         ClassName(const ClassName&) = delete; \