fix(dsn): remove pLimit.clearQueue() that caused silent hangs (#411)

pLimit.clearQueue() removes queued items from the internal queue, but the
promises returned by limit() for those cleared items never settle. When
used with Promise.all(), this causes the entire call to hang indefinitely.

The earlyExit flag already causes queued tasks to return immediately when
they reach the front of the queue, making clearQueue() both redundant and
harmful.

Bug: scanCodeForFirstDsn (stopOnFirst=true) would hang on any project with
enough source files to exceed the concurrency limit of 50. Commands that
relied on DSN auto-detection (e.g., 'sentry trial list' without explicit
org) would silently exit with code 0 and no output.

Author: BYK