Use apt-get instead of apt to fix warning

Signed-off-by: Liviu-Mihail Concioiu <liviu.concioiu@gmail.com>

Author: liviuconcioiu

.github/workflows/build.yml

@@ -43,8 +43,8 @@ jobs:
                   submodules: true
             - name: Install Sphinx-doc
               run: |
-                  sudo apt update
-                  sudo apt install -y sphinx-doc python3-sphinx
+                  sudo apt-get update
+                  sudo apt-get install -y sphinx-doc python3-sphinx
             - name: Install gettext
               run: sudo apt-get install -y gettext
             - name: Install git-restore-mtime