nvim: lsp: Switch to pylsp

pyls is deprecated and not supported in nvim-lspconfig anymore.

The supported python language server is here.
https://github.com/python-lsp/python-lsp-server

nvim/.config/nvim/lua/lsp.lua

@@ -172,7 +172,7 @@ function set_snippet_capabilities()
   return capabilities
 end
 
-local servers = { 'hls', 'rust_analyzer', 'pyls', 'tsserver' }
+local servers = { 'hls', 'rust_analyzer', 'pylsp', 'tsserver' }
 for _, lsp in ipairs(servers) do
   nvim_lsp[lsp].setup {
     on_attach = on_attach,