Add **kwargs note to task docs

develop-docs/backend/application-domains/tasks/index.mdx

@@ -25,7 +25,7 @@ from sentry.taskworker.retry import Retry
     retry=Retry(times=3, on=(ConnectionError,)),
     processing_deadline_duration=60
 )
-def do_work(organization_id: int, issue_id: int, **kwargs) -> None:
+def do_work(organization_id: int, issue_id: int, **kwargs: Any) -> None:
     ...
 ```
 
@@ -42,9 +42,12 @@ When defining tasks there are some constraints:
   deadline has elapsed, it will be killed by the worker runtime. Tasks that are
   killed for execution duration are not automatically retried.
 
-- All tasks must be assigned to a 'namespace'. A namespace is a group of related
+- Tasks _must_ be assigned to a 'namespace'. A namespace is a group of related
   tasks that are operated together and share a backlog.
 
+- Tasks _should_ take `**kwargs: Any` as their final argument.
+  Without it, adding parameters is more complex and requires multiple deploys.
+
 - The return value of a task is not stored and ignored by workers.
 
 - The module containing a task _must_ be added to `TASKWORKER_IMPORTS` in
@@ -96,7 +99,7 @@ is inherited.
     namespace=issues_tasks,
     retry=Retry(times=3, times_exceeded=LastAction.Deadletter),
 )
-def deliver_issue_webhook(organization_id: int, group_id: int) -> None:
+def deliver_issue_webhook(organization_id: int, group_id: int, **kwargs: Any) -> None:
    ...
 ```
 
@@ -119,7 +122,7 @@ needs to stagger retries, it can use a delayed retry.
     namespace=issues_tasks,
     retry=Retry(times=3, on=(IntegrationError, ), delay=30)
 )
-def fetch_commits(repository_id: int) -> None:
+def fetch_commits(repository_id: int, **kwargs: Any) -> None:
     ...
 ```
 
@@ -142,7 +145,7 @@ saturated by tasks running for unbounded amounts of time.
     # Extended from the default 10
     processing_deadline_duration=60
 )
-def fetch_commits(repository_id: int) -> None:
+def fetch_commits(repository_id: int, **kwargs: Any) -> None:
     ...
 ```
 
@@ -172,7 +175,7 @@ skipped if they are stale and their results are no longer relevant.
     namespace=issues_tasks,
     expires=timedelta("5 minutes"),
 )
-def deliver_issue_webhook(organization_id: int, group_id: int):
+def deliver_issue_webhook(organization_id: int, group_id: int, **kwargs: Any):
     ...
 ```
 
@@ -206,7 +209,7 @@ execution.
     namespace=issues_tasks,
     at_most_once=True,
 )
-def deliver_issue_webhook(organization_id: int, group_id: int) -> None:
+def deliver_issue_webhook(organization_id: int, group_id: int, **kwargs: Any) -> None:
    ...
 
 ```
@@ -289,7 +292,7 @@ With an external namespace you can register and spawn **external tasks**.
 
 ```python
 @launchpad_tasks.register(name="launchpad.task.name")
-def run_process(org_id: int, project_id: int, payload: bytes) -> None:
+def run_process(org_id: int, project_id: int, payload: bytes, **kwargs: Any) -> None:
     pass
 
 
@@ -360,7 +363,7 @@ issues_tasks = taskregistry.create_namespace(
 
 # register tasks within a namespace
 @instrumented_task(name="tasks.do_work", namespace=issues_tasks)
-def do_work(**kwargs):
+def do_work(**kwargs: Any):
    ...
 ```