add-apt-repository isn't found in docker image

Author: texus

.github/workflows/ci.yml

@@ -16,6 +16,8 @@ jobs:
 
       - name: Install dependencies
         run: |
+          apt update
+          apt install software-properties-common
           add-apt-repository --yes ppa:texus/raylib
           apt-get update
           apt-get -y install g++-$GCC_VERSION clang-$CLANG_VERSION clang-tidy-$CLANG_VERSION ninja-build cppcheck