* vlib/json2: remove duplicated sumtype todo fixture
The todo file was copied into decoder_tests/ by a60fb589 while the
identical original stayed in tests/. Nothing references either copy
(they are uncompiled .vv notes), so drop the newer duplicate.
* examples: remove unreferenced duplicate veb_assets example
veb_assets_example.v is byte-identical to the sibling veb_assets.v and
referenced nowhere (docs, tests, CI). Keep the original, drop the copy.
---------
Co-authored-by: qp <168933756+gabytz777@users.noreply.github.com>