feat!: track parser revision in Lua

Problem: Tracking parser revision in lockfile and allowing override
through the parsers module complicates the code. In addition, only
revision changes are handled robustly, not changes to other installation
info.

Solution: Track parser revision in the parsers module directly. Reload
parser table on every install or update call. Support modifying parser
table in a `User TSUpdate` autocommand.

lua/nvim-treesitter/_meta/parsers.lua

@@ -0,0 +1,47 @@
+---@meta
+error('Cannot require a meta file')
+
+---@class InstallInfo
+---
+---URL of parser repo (Github/Gitlab)
+---@field url string
+---
+---Commit hash of parser to download (compatible with queries)
+---@field revision string
+---
+---Files to include when compiling (`src/parser.c` and optionally `src/scanner.c')
+---@field files string[]
+---
+---Branch of parser repo to download (if not default branch)
+---@field branch? string
+---
+---Location of `grammar.js` in repo (if not at root, e.g., in a monorepo)
+---@field location? string
+---
+---Repo does not contain a `parser.c`; must be generated from grammar first
+---@field generate? boolean
+---
+---Parser needs to be generated from `grammar.json` (generating from `grammar.js` requires npm)
+---@field generate_from_json? boolean
+---
+---Parser repo is a local directory; overrides `url`, `revision`, and `branch`
+---@field path? string
+
+---@class ParserInfo
+---
+---Information necessary to build and install the parser (empty for query-only language)
+---@field install_info? InstallInfo
+---
+---List of Github users maintaining the queries for Neovim
+---@field maintainers? string[]
+---
+---List of other languages to install (e.g., if queries inherit from them)
+---@field requires? string[]
+---
+---Language support tier, maps to "core", "stable", "community", "unmaintained"
+---@field tier integer
+---
+---Explanatory footnote text to add in SUPPORTED_LANGUAGES.md
+---@field readme_note? string
+
+---@alias nvim-ts.parsers table<string,ParserInfo>