Drop clang-format job

With updated Clang, the job won't pass. Reformating the code just for
the sake of the job seems futile.

.gitlab-ci.yml

@@ -24,7 +24,6 @@ variables:
   SCAN_BUILD: "scan-build-${CLANG_VERSION}"
   LLVM_SYMBOLIZER: "/usr/lib/llvm-${CLANG_VERSION}/bin/llvm-symbolizer"
   ASAN_SYMBOLIZER_PATH: "/usr/lib/llvm-${CLANG_VERSION}/bin/llvm-symbolizer"
-  CLANG_FORMAT: "clang-format-${CLANG_VERSION}"
 
   CFLAGS_COMMON: -fno-omit-frame-pointer -fno-optimize-sibling-calls -O1 -g -Wall -Wextra
 
@@ -342,18 +341,6 @@ black:
     expire_in: "1 week"
     when: on_failure
 
-clang-format:
-  <<: *precheck_job
-  script:
-    - if [ -r .clang-format ]; then "${CLANG_FORMAT}" -i -style=file $(git ls-files '*.c' '*.h'); fi
-    - git diff > clang-format.patch
-    - if test "$(git status --porcelain | grep -Ev '\?\?' | wc -l)" -gt "0"; then git status --short; exit 1; fi
-  artifacts:
-    paths:
-      - clang-format.patch
-    expire_in: "1 week"
-    when: on_failure
-
 coccinelle:
   <<: *precheck_job
   script: