Update nvim plugins rustaceanvim and venv-selector

[EnriqueVidal]

This pull request mainly updates Neovim plugin configurations to improve Copilot integration, update plugin versions, and refine dependencies. The most significant changes are the addition and configuration of the new Copilot LSP plugin, updates to plugin versions in the lockfile, and improvements to plugin dependency management.

Copilot integration and configuration

• Added and configured the copilot-lsp plugin in avante-nvim.lua, including setup for Copilot and key mappings for accepting suggestions. Also introduced a new plugin file copilot-lsp.lua for custom initialization and keybindings. [1] [2]

Plugin version updates

• Updated multiple plugin versions and commits in lazy-lock.json, ensuring the latest features and fixes for core plugins such as LuaSnip, alpha-nvim, fzf-lua, gitsigns.nvim, copilot.lua, and others.
• Updated rustaceanvim to version ^6 in its configuration file.

Dependency and configuration improvements

• Improved dependency declarations for mason-lspconfig and venv-selector plugins, including more explicit and organized dependency lists and options. Added build instructions for nvim-dap-python and optional dependencies for better Python support. [1] [2]
• Minor configuration tweaks for nvim-lspconfig and lspsaga, such as simplifying capability passing and removing unnecessary lazy loading. [1] [2]

Miscellaneous

• Added pid to the .gitignore file for MPD configuration, improving local development hygiene.