Update .gitlab-ci.yml file

Do not care for non-prototypes for clang-testing job 

.gitlab-ci.yml

@@ -342,9 +342,9 @@ build-clang:
 build-clang-testing:
   <<: *job_build
 
-  image: debian:testing-slim
+  extends: build-clang
 
-  allow_failure: true
+  image: debian:testing-slim
 
   artifacts:
     paths:
@@ -353,24 +353,4 @@ build-clang-testing:
 
   variables:
     CC: clang
-    CFLAGS: -Wno-cast-align
-
-  script:
-    - - |
-       echo -e "\e[0Ksection_start:`date +%s`:apt_toolchain[collapsed=true]\r\e[0KInstalling toolchain packages"
-      - apt-get install clang
-      - |
-       echo -e "\e[0Ksection_end:`date +%s`:apt_toolchain\r\e[0K"
-
-    - - |
-       echo -e "\e[0Ksection_start:`date +%s`:apt_development[collapsed=true]\r\e[0KInstalling development packages"
-      - apt-get install libsdl2-mixer-dev libpng-dev libcurl4-openssl-dev libgme-dev libopenmpt-dev
-      - |
-       echo -e "\e[0Ksection_end:`date +%s`:apt_development\r\e[0K"
-
-    - - |
-       echo -e "\e[0Ksection_start:`date +%s`:make[collapsed=false]\r\e[0KCompiling SRB2"
-      - make --directory=src --keep-going CCACHE=1 ERRORMODE=1 NONX86=1 || make --directory=src --keep-going CCACHE=1 ERRORMODE=1 NONX86=1
-      - |
-       echo -e "\e[0Ksection_end:`date +%s`:make\r\e[0K"
-
+    CFLAGS: -Wno-cast-align -Wno-deprecated-non-prototype