reserve space for `code-action-hint` only if `lsp.enable`

I have lsp.enable = false in my config, but I love the light-bulb indicator when I have a LSP running. However, as you may guess, I rarely use LSPs, as I rely more on tree-sitter grammars. It'd be nice if the gutter was smaller by default, then extend when I do :toggle lsp.enable (FYI, I have a macro for that) to set it to true, then become smaller after I toggle again.

I could just modify my macro to do that for me, but there's the bug #13187; and even if the bug was fixed, the config-line would be long, hacky, and unreliable (risk of de-sync between config-fields). So I'd have to define a separate macro, which would also be "hacky", unless the config system supported inner mutation instead of declarative arrays (#8853)