ci/mingw: drop useless -Wno-error flags

Will prevent merging incorrect code like in #8260

Reviewed-by: Yonggang Luo <luoyonggang@gmail.com>
Acked-by: David Heidelberg <david.heidelberg@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21244>

.gitlab-ci/build/gitlab-ci.yml

@@ -646,18 +646,11 @@ debian-mingw32-x86_64:
     UNWIND: "disabled"
     C_ARGS: >
       -Wno-error=format
-      -Wno-error=format-extra-args
-      -Wno-error=deprecated-declarations
       -Wno-error=unused-function
       -Wno-error=unused-variable
       -Wno-error=unused-but-set-variable
-      -Wno-error=unused-value
-      -Wno-error=switch
-      -Wno-error=parentheses
-      -Wno-error=missing-prototypes
       -Wno-error=sign-compare
       -Wno-error=narrowing
-      -Wno-error=overflow
     CPP_ARGS: $C_ARGS
     GALLIUM_DRIVERS: "swrast,d3d12,zink"
     VULKAN_DRIVERS: "swrast,amd,microsoft-experimental"