the pid of async_limiter in the query's context will be invalid because we stop it
at the end of reading. So clear it up from query's context before returning back.
BTW, I found this issue according to the following crash:
```
[error] GenServer #PID<0.647.0> terminating
** (stop) exited in: GenServer.call(#PID<0.648.0>, {:get_and_update, #Function<0.21809672/1 in Ash.Actions.Read.AsyncLimiter.async_or_inline/3>}, 5000)
** (EXIT) no process: the process is not alive or there's no process currently associated with the given name, possibly because its application isn't started
(elixir 1.16.0) lib/gen_server.ex:1114: GenServer.call/3
(ash 2.19.3) lib/ash/actions/read/async_limiter.ex:26: Ash.Actions.Read.AsyncLimiter.async_or_inline/3
(elixir 1.16.0) lib/enum.ex:1708: anonymous fn/3 in Enum.map/2
(elixir 1.16.0) lib/enum.ex:4399: anonymous fn/3 in Enum.map/2
(elixir 1.16.0) lib/stream.ex:1816: anonymous fn/3 in Enumerable.Stream.reduce/3
(elixir 1.16.0) lib/enum.ex:4842: Enumerable.List.reduce/3
(elixir 1.16.0) lib/stream.ex:1828: Enumerable.Stream.do_each/4
(elixir 1.16.0) lib/enum.ex:4399: Enum.map/2
(ash 2.19.3) lib/ash/actions/read/relationships.ex:39: Ash.Actions.Read.Relationships.fetch_related_records/2
(ash 2.19.3) lib/ash/actions/read/relationships.ex:23: Ash.Actions.Read.Relationships.load/3
(ash 2.19.3) lib/ash/actions/read/read.ex:237: Ash.Actions.Read.do_run/3
(ash 2.19.3) lib/ash/actions/read/read.ex:49: anonymous fn/3 in Ash.Actions.Read.run/3
(ash 2.19.3) lib/ash/actions/read/read.ex:48: Ash.Actions.Read.run/3
(ash 2.19.3) lib/ash/api/api.ex:2301: Ash.Api.page/3
(ash 2.19.3) lib/ash/api/api.ex:2258: Ash.Api.page!/3
...
```
Signed-off-by: Tw <tw19881113@gmail.com>