feat(workflows-sdk): Allow a step to not define an expected input (#5775)

**What**
Allow a step to not define an expected input, previously even if no input was expected, an object was always expected to be passed to the stepFunction inside the workflow composition. Now
```ts
const stepWithoutArgs = createStep("step1", () => {
  return new StepResponse("string")
})

const stepWithoutExepectedInput = createStep("step2", (_: {}, context) => {
  console.log("input", _) // {}
  return new StepResponse("string")
})

const workflow = createWorkflow("workflow1", () => {
  stepWithoutArgs()
  return stepWithoutExepectedInput()
})

workflow()
  .run()
  .then((res) => {
    console.log(res.result) // string
  })
```

packages/workflows-sdk/src/utils/_test.ts

@@ -0,0 +1,27 @@
+import { createStep, createWorkflow, StepResponse } from "./composer"
+
+const step1 = createStep("step1", async (input: {}, context) => {
+  console.log("step1", input) // Here the input will be `{}` and the createWorkflow does not have to provide an input
+  return new StepResponse({ step1: "step1" })
+})
+
+const step2 = createStep("step2", async (input: string, context) => {
+  console.log("step2", input) // Here the input will be the string value `step1`
+  return new StepResponse({ step2: "step2" })
+})
+
+const step3 = createStep("step3", async () => {
+  return new StepResponse({ step3: "step3" })
+})
+
+const workflow = createWorkflow("workflow", function () {
+  const step1Res = step1()
+  step3()
+  return step2(step1Res.step1)
+})
+
+workflow()
+  .run({})
+  .then((res) => {
+    console.log(res.result) // result: { step2: "step2" }
+  })