[metacity] ci: stop using clang for coverity job

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 1d70b1be2cfdd55f5af3108ec2ddf9f06a960f5a
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Sep 12 15:15:34 2020 +0300

    ci: stop using clang for coverity job

 .gitlab-ci.yml | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e66b5974..be83f3e7 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -53,20 +53,22 @@ ubuntu:
 coverity:
   image: ubuntu:devel
   stage: analysis
+  variables:
+    # cov-build doesn’t like GLIB_DEPRECATED_ENUMERATOR
+    CFLAGS: '-DGLIB_DISABLE_DEPRECATION_WARNINGS'
   when: manual
   before_script:
     - apt-get update
     - *install-ubuntu-dependencies
     - apt-get install -q -y --no-install-recommends
                       ca-certificates
-                      clang
                       curl
   script:
     - curl https://scan.coverity.com/download/linux64
       --data "token=$COVERITY_TOKEN&project=metacity"
       --output /tmp/coverity_tool.tgz
     - tar zxf /tmp/coverity_tool.tgz
-    - CC=clang ./autogen.sh --disable-Werror
+    - ./autogen.sh --disable-Werror
     - ./cov-analysis-linux64-*/bin/cov-build --dir cov-int make
     - tar czf cov-int.tar.gz cov-int
     - curl --form token=$COVERITY_TOKEN