Various CI improvments

- Fix installation of package dependencies in CI
- Remove not needed chmod
- Only build when PKGBUILD are changed

.gitlab-ci.yml

@@ -13,15 +13,18 @@ makepkg:
     - pacman --sync --refresh --sysupgrade --noconfirm
     - pacman --sync --noconfirm base-devel devtools
     - useradd --home-dir /root --groups root,wheel --shell /bin/bash build
-    - chmod 770 /root
+    - "echo 'build ALL = NOPASSWD: /usr/bin/pacman' > /etc/sudoers.d/build"
   script:
     - ulimit -c 0
-    - sudo -u build -- makepkg --syncdeps
+    - sudo -u build -- makepkg --syncdeps --noconfirm
   artifacts:
     name: $CI_PROJECT_NAME-$CI_COMMIT_REF_NAME-$CI_COMMIT_SHA
     expire_in: 1 week
     paths:
       - "*.pkg.tar.xz"
+  only:
+    changes:
+      - PKGBUILD
 
 commitpkg:
   stage: deploy