build: Remove -Wno-module-file-config-mismatch

The -Wno-module-file-config-mismatch flag was intended to suppress
module build errors related to incompatible configurations. However, it
resulted in cryptic failures without adequate explanations. Given that
we've now disabled module builds for targets using incompatible flags
(such as RTTI or exceptions), this suppression flag is no longer needed.

Bug: 403415459
Change-Id: I54221437793b958adf0b6415bb9dd3512e25aa0a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6606236
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Fumitoshi Ukai <ukai@google.com>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1467958}