Use always bundled afterimage which contains many fixes

that the obsolete upstream version does not (unmaintained package)

Fixes #14247

This is an exception of the general rule introduced by 2b3250d

cmake/modules/RootBuildOptions.cmake

@@ -80,7 +80,7 @@ endfunction()
 ROOT_BUILD_OPTION(arrow OFF "Enable support for Apache Arrow")
 ROOT_BUILD_OPTION(asimage ON "Enable support for image processing via libAfterImage")
 ROOT_BUILD_OPTION(asserts OFF "Enable asserts (defaults to ON for CMAKE_BUILD_TYPE=Debug and/or dev=ON)")
-ROOT_BUILD_OPTION(builtin_afterimage OFF "Build bundled copy of libAfterImage")
+ROOT_BUILD_OPTION(builtin_afterimage ON "Build bundled copy of libAfterImage")
 ROOT_BUILD_OPTION(builtin_cfitsio OFF "Build CFITSIO internally (requires network)")
 ROOT_BUILD_OPTION(builtin_clang ON "Build bundled copy of Clang")
 ROOT_BUILD_OPTION(builtin_cling ON "Build bundled copy of Cling. Only build with an external cling if you know what you are doing: associating ROOT commits with cling commits is tricky.")