Split of "Mass update arvr/third-party/pybind11 to point to third-party/pybind11" #2 (#1433)

Summary:
Pull Request resolved: #1433

Incrementally updating this over

Differential Revision: D52018058

fbshipit-source-id: fc460e8ca59c4e24828f5a199de011004755d29a

Author: 8Keep

exir/_serialize/TARGETS

@@ -18,8 +18,8 @@ cpp_python_extension(
         "//executorch/sdk/etdump/...",
     ],
     deps = [
-        "fbsource//arvr/third-party/pybind11:pybind11",
         "fbsource//third-party/flatbuffers:flatc_library",
+        "fbsource//third-party/pybind11/2.6.2:pybind11",
     ],
 )
 

exir/_serialize/bindings.cpp

@@ -8,8 +8,8 @@
 
 #include <flatbuffers/flatc.h> // @manual=fbsource//third-party/flatbuffers:flatc_library
 #include <flatbuffers/idl.h> // @manual=fbsource//third-party/flatbuffers:flatc_library
-#include <pybind11/pybind11.h> // @manual=fbsource//arvr/third-party/pybind11:pybind11
-#include <pybind11/stl.h> // @manual=fbsource//arvr/third-party/pybind11:pybind11
+#include <pybind11/pybind11.h> // @manual=fbsource//third-party/pybind11/2.6.2:pybind11
+#include <pybind11/stl.h> // @manual=fbsource//third-party/pybind11/2.6.2:pybind11
 
 namespace exir {
 namespace {