Pin clang-format to version 17 in CI (hopefully temporarily)

.clang-format

@@ -1,6 +1,6 @@
 ---
 Language: Cpp
-Standard: c++17
+Standard: c++20
 AccessModifierOffset: -4
 AlignAfterOpenBracket: Align
 AlignConsecutiveAssignments: true

.gitlab-ci.yml

@@ -454,8 +454,9 @@ linting:
   tags: [docker]
   before_script:
     - apk update && apk add make git python3 py3-pip qt6-qtdeclarative-dev
-    - apk add clang-extra-tools --repository=http://dl-cdn.alpinelinux.org/alpine/edge/main
-    - export PATH="$PATH:/root/.local/bin"
+    # clang18 seems to mess with the emit keyword when using the `->` operator
+    - apk add clang17-extra-tools --repository=http://dl-cdn.alpinelinux.org/alpine/edge/main
+    - export PATH="$PATH:/usr/lib/llvm17/bin/:/root/.local/bin"
     - pip3 install --break-system-packages --user reuse
   script:
     - make lint