[SYCL][CI][diagnostic] Don't let set -e abort the crash-capture step
GitHub runs the step's bash with -e -o pipefail. After the reg.exe probes, the
cdb 'find' over a non-existent Windows Kits path returned nonzero and -e aborted
the whole step before the test ran -- so no log was written and no artifact
uploaded (only the three 'Invalid syntax' reg errors showed). Add set +e +o
pipefail (this is a best-effort diagnostic with several intentionally-nonzero
probes) and guard find to existing dirs only.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>