[ci] Change python version 2.7 to 3.8 (#930)

Author: JSUYA

.github/workflows/build.yml

@@ -30,7 +30,7 @@ jobs:
         run: |
           sudo add-apt-repository ppa:deadsnakes/ppa
           sudo apt update
-          sudo apt install -y libncurses5 python2.7 libpython2.7 gettext \
+          sudo apt install -y libncurses5 python3.8 libpython3.8  gettext \
             libkf5itemmodels5 libkf5kiowidgets5 libkchart2 dbus-x11 gnome-keyring
           curl https://download.tizen.org/sdk/Installer/tizen-studio_6.0/web-cli_Tizen_Studio_6.0_ubuntu-64.bin -o install.bin
           chmod a+x install.bin