Update [editing-support.nvim-context-vt] community plugin to fix error notice(s)

[luisjakon]

Due to an api change on the ["andersevenrud/nvim_context_vt"] base package, an error notice gets displayed when toggling virtual text on/off.

The following fixes the error:

-- astrocommunity/editing-support/nvim-context-vt/init.lua
{
  "andersevenrud/nvim_context_vt",
  event = "User AstroFile",
  cmd = { "NvimContextVtToggle" },
  dependencies = {
    "AstroNvim/astrocore",
    ---@type AstroCoreOpts
    opts = {
      mappings = {
        n = {
          ["<Leader>uv"] = {
            function() require("nvim_context_vt").toggle_context() end,
            desc = "Toggle virtual text context",
          },
        },
      },
    },
  },
},