feat: run.ctx tidying and additions

.changeset/giant-plums-smash.md

@@ -0,0 +1,18 @@
+---
+"@trigger.dev/sdk": patch
+---
+
+Added and cleaned up the run ctx param:
+
+- New optional properties `ctx.run.parentTaskRunId` and `ctx.run.rootTaskRunId` reference the current run's root/parent ID.
+- Removed deprecated properties from `ctx`
+- Added a new `ctx.deployment` object that contains information about the deployment associated with the run.
+
+We also update `metadata.root` and `metadata.parent` to work even when the run is a "root" run (meaning it doesn't have a parent or a root associated run). This now works:
+
+```ts
+metadata.root.set("foo", "bar");
+metadata.parent.set("baz", 1);
+metadata.current().foo // "bar"
+metadata.current().baz // 1
+```