Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -26,6 +26,7 @@ workflow:
     - python -m pip install --upgrade pip 
     - python -m pip install conan
     # Install prerequisite for git-gui and gitk
+    - sudo yum -y update
     - sudo yum -y install tcl-devel tk-devel
     # Build git with conan
     - conan profile detect --force