nvim: Simplify molten statusline function

Instead of doing all kinds of security checks beforehand, we simply wrap
the molten kernel check into a lua protected call and return an empty
result if we would error. We only return the symbol if we don't error
and we have an active kernel.

nvim/.config/nvim/lua/plugins/ui.lua

@@ -8,26 +8,28 @@ return {
 			-- if molten exists, is initialized and connected to a kernel
 			-- show it in the statusline
 			local function molten()
-				local function checked_pynvim(_, exitcode)
+				-- we don't have access to python, disregard element
+				if has_pynvim == 0 then
+					return ""
+				elseif has_pynvim == 1 then
+					local status_ok, res = pcall(function()
+						return require("molten.status").kernels() ~= ""
+					end)
+					if status_ok and res then
+						return "󱪄"
+					end
+					return ""
+				-- we don't know if we have python yet, start a check
+				else
+					vim.system({ "poetry", "env", "info", "-p" }, { text = true }, function(_, exitcode)
 						if exitcode == 0 then
 							has_pynvim = 1
 						else
 							has_pynvim = 0
 						end
+					end)
+					has_pynvim = 0
 				end
-				if has_pynvim == 0 then
-					return ""
-				elseif has_pynvim == -1 then
-					vim.fn.jobstart({ "python", "-c", "from neovim import VERSION" }, { on_exit = checked_pynvim })
-				end
-				if
-					has_pynvim == 1
-					and require("core.util").is_available("molten.status")
-					and require("molten.status").kernels() ~= ""
-				then
-					return "󱪄"
-				end
-				return ""
 			end
 
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