[BNPL][Clank] Remove Klarna from Field trial testing config for BNPL

Bug: 369428863
Change-Id: I94301f40af7c81018a450fc45ae85eba5cdd8d94
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7833656
Reviewed-by: Vinny Persky <vinnypersky@google.com>
Commit-Queue: Viplav Kadam <viplavkadam@google.com>
Cr-Commit-Position: refs/heads/main@{#1628061}
NOKEYCHECK=True
GitOrigin-RevId: 59d2934ce6786b35cfbc797ad2e3baaaa1278fa7