[build]: add uninstall cmake target (#3511)

CMakeLists.txt

@@ -37,6 +37,17 @@ include(BuildOptions)
 # Main sources directory (the second parameter sets the output directory name to raylib)
 add_subdirectory(src raylib)
 
+# Uninstall target
+if(NOT TARGET uninstall)
+  configure_file(
+    "${CMAKE_MODULE_PATH}/Uninstall.cmake"
+    "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake"
+    IMMEDIATE @ONLY)
+
+  add_custom_target(uninstall
+    COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake)
+endif()
+
 if (${BUILD_EXAMPLES})
   MESSAGE(STATUS "Building examples is enabled")
   add_subdirectory(examples)