Remove unnecessary files from the generated vsix

[stackoverflow]

• Fix missing runtime dependency: vscode-languageclient 10 requires
  vscode-languageserver-textdocument, which wasn't in the
  .vscodeignore allow-list, so it was left out of the vsix.
• Remove the hand-maintained list of dependencies from .vscodeignore.
  vsce already packages only production dependencies, so node_modules can be allow-listed in
  general and the list can't go out of date on future dependency bumps.
• Stop shipping source maps (*.map) and TypeScript declarations (*.d.ts) from out/ and node_modules.
• Only ship the runtime files of web-tree-sitter (tree-sitter.cjs,
  tree-sitter.wasm, package.json, LICENSE).
• Stop shipping package-lock.json.
• Stop copying tree-sitter.wasm into out/. Parser.init() loads it
  from node_modules/web-tree-sitter/, so the copy was never used.
• Create out/ instead of the unused out/grammar/ directory in the
  build:tree-sitter scripts.

I tested the generated vsix locally and it seems to be working fine.