Remove unused CMake find module for OSMesa

CMake/modules/FindOSMesa.cmake

@@ -1,18 +0,0 @@
-# Try to find OSMesa on a Unix system
-#
-# This will define:
-#
-#   OSMESA_LIBRARIES   - Link these to use OSMesa
-#   OSMESA_INCLUDE_DIR - Include directory for OSMesa
-#
-# Copyright (c) 2014 Brandon Schaefer <[email protected]>
-
-if (NOT WIN32)
-
-  find_package (PkgConfig)
-  pkg_check_modules (PKG_OSMESA QUIET osmesa)
-
-  set (OSMESA_INCLUDE_DIR ${PKG_OSMESA_INCLUDE_DIRS})
-  set (OSMESA_LIBRARIES   ${PKG_OSMESA_LIBRARIES})
-
-endif ()