siso: add ./obj/content/test/content_browsertests__library/prerender_browsertest.o to exit137_list

Bug: b/289968566
Change-Id: I63476e974b816460aa62c0069df59b8bb73fb583
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5428276


Commit-Queue: Fumitoshi Ukai <ukai@google.com>
Reviewed-by: Junji Watanabe <jwata@google.com>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Fumitoshi Ukai <ukai@google.com>
Cr-Commit-Position: refs/heads/main@{#1283015}