fix: re-export TaskGroup from parallel.types.beta and silence reportDeprecated

Two related fixes for the breaking-change detector against the pre-0.6.0
baseline:

* The new `parallel/types/beta/task_group.py` shim wasn't re-exported from
  `parallel/types/beta/__init__.py`, so baseline tests doing
  `from parallel.types.beta import TaskGroup` failed pyright. Add the
  re-export.

* The `beta.taskgroup` resource is now `@deprecated` (we recommend GA),
  but baseline tests don't have a `# pyright: reportDeprecated=false`
  marker. Promote the per-file marker to project level — deprecation is a
  runtime concern, not a type error.

Author: NormallyGaussian

pyproject.toml

@@ -158,6 +158,11 @@ reportOverlappingOverload = false
 
 reportImportCycles = false
 reportPrivateUsage = false
+# Deprecation is a runtime concern; type-check warnings produce noise when the
+# breaking-change detector compares against pre-deprecation baseline tests.
+# Newly-generated tests already add a per-file `# pyright: reportDeprecated=false`
+# marker for deprecated resources, so this just promotes that to project-level.
+reportDeprecated = false
 
 [tool.mypy]
 pretty = true

src/parallel/types/beta/__init__.py

@@ -4,6 +4,7 @@
 
 from .webhook import Webhook as Webhook
 from .mcp_server import McpServer as McpServer
+from .task_group import TaskGroup as TaskGroup
 from .usage_item import UsageItem as UsageItem
 from .error_event import ErrorEvent as ErrorEvent
 from .findall_run import FindAllRun as FindAllRun, FindallRun as FindallRun