Problem:
During startup, we manually trigger a useless and misleading `OptionSet`
event, which doesn't set `v:option_*` values (this is a limitation of
`nvim_exec_autocmds`).
ad4bc2d90c/runtime/lua/vim/_core/defaults.lua (L939).
Solution:
The `nvim_exec_autocmds('OptionSet',…)` call does not serve any purpose
since 5cbb9d613b, so just drop it.
98098d8466