Remove `FixCursorHold.nvim` — superseded by Neovim 0.10's native CursorHold fix

[ooloth]

Why

FixCursorHold.nvim patches a CursorHold event performance bug that was resolved natively in Neovim 0.10, making it an unmaintained and redundant dependency for a config that already requires Neovim 0.10+.

Current state

lua/config/plugins/specs/neotest.lua lists 'antoinemadec/FixCursorHold.nvim' in the neotest plugin's dependencies table. The config already gates other features on Neovim 0.10 (e.g., ts-comments.lua uses enabled = vim.fn.has('nvim-0.10.0') == 1). The plugin's author documented that it is no longer needed once Neovim ships the native CursorHold fix (which shipped in 0.10). The repository has had no commits since 2022.

Ideal state

• lua/config/plugins/specs/neotest.lua does not list antoinemadec/FixCursorHold.nvim in its dependencies table.
• lazy.nvim installs and manages one fewer plugin on next sync.
• lazy-lock.json (once committed) records no entry for antoinemadec/FixCursorHold.nvim.

Starting points

• lua/config/plugins/specs/neotest.lua — the dependencies table listing 'antoinemadec/FixCursorHold.nvim'.

QA plan

1. Open lua/config/plugins/specs/neotest.lua — expect antoinemadec/FixCursorHold.nvim to be absent from the dependencies list.
2. Start Neovim and run :Lazy sync — expect no error referencing FixCursorHold.nvim.
3. Open a test file and run :Neotest run — expect tests to execute and results to appear normally.
4. Move the cursor slowly over a test file — expect no CursorHold lag or Neovim errors.

Done when

antoinemadec/FixCursorHold.nvim is removed from neotest.lua dependencies and neotest continues to run tests without errors.