refactor: async processes

tests/manage/process_spec.lua

@@ -0,0 +1,20 @@
+---@module 'luassert'
+local Async = require("lazy.async")
+local Process = require("lazy.manage.process")
+
+describe("process", function()
+  it("runs sync", function()
+    local lines = Process.exec({ "echo", "-n", "hello" })
+    assert.are.same({ "hello" }, lines)
+  end)
+
+  it("runs sync from async context", function()
+    local lines ---@type string[]
+    local async = Async.new(function()
+      lines = Process.exec({ "echo", "-n", "hello" })
+    end)
+    async:wait()
+
+    assert.are.same({ "hello" }, lines)
+  end)
+end)