Remove our pybind target headers from gitignore. They were already committed, but also ignored for no reason.

Author: adalisk-emikhaylov

.gitignore

@@ -11,7 +11,6 @@
 /test/**/bin
 /test/**/obj
 parallel-hashmap/
-pybind11/
 /examples/cxx.txt
 /examples/c/output
 /examples/csharp/c_library