fix(devserver): exclude .artifacts from granian reload watcher (#117609)

Fixes getsentry/self-hosted#4379 
Granian's watchfiles-based reloader watches the entire repo directory by
default. The TeeStream introduced in #117486 writes all
honcho output to .artifacts/dev.log inside the repo root, which
triggered an infinite reload cycle: server logs →-> dev.log updated ->
watchfiles detects change -> granian reloads -> repeat.

Fix by passing reload_ignore_dirs=[".artifacts"] to Granian so
watchfiles skips that directory. The option is surfaced through the
existing options dict so it can be overridden via SENTRY_WEB_OPTIONS if
needed.

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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: kitlord

src/sentry/services/http.py

@@ -21,6 +21,7 @@ def _run_server(options: dict[str, Any]):
         blocking_threads=options["threads"],
         respawn_failed_workers=True,
         reload=options["reload"],
+        reload_ignore_dirs=options.get("reload-ignore-dirs"),
         reload_ignore_worker_failure=options["reload-ignore-worker-failure"],
         process_name=options["proc-name"],
         workers_lifetime=options["max-worker-lifetime"],
@@ -67,6 +68,7 @@ def __init__(
         options.setdefault("log-enabled", True)
         options.setdefault("proc-name", "sentry")
         options.setdefault("reload", reload)
+        options.setdefault("reload-ignore-dirs", [".artifacts"])
         options.setdefault("reload-ignore-worker-failure", reload)
         options.setdefault("workers-kill-timeout", 3 if reload else 30)
         options.setdefault("max-worker-lifetime", None)