Remove exportsfiles(["LICENSE"]).

The file doesn't exist, and using the exported target causes downstream errors.

For one, TensorFlow's license checker errors on these non-existing LICENSE files

PiperOrigin-RevId: 500257122

pybind11_abseil/BUILD

@@ -6,8 +6,6 @@ package(default_visibility = ["//visibility:public"])
 
 
 licenses(["notice"])
 licenses(["notice"])
 
 
-exports_files(["LICENSE"])
-
 pybind_library(
 pybind_library(
     name = "absl_casters",
     name = "absl_casters",
     hdrs = ["absl_casters.h"],
     hdrs = ["absl_casters.h"],