Revert "ci: try build appimage on ubuntu 18.04"

This reverts commit dc7c281.

Author: variar

.github/workflows/ci-build.yml

@@ -107,13 +107,13 @@ jobs:
             cmake_opts:
 
           - os: ubuntu_appimage
-            os_version: 18.04
+            os_version: 20.04
             arch: x64
             artifacts_id: appimage
             package_suffix: AppImage
-            container_root: docker/ubuntu18.04_qt5.15
-            container: variar/klogg_ubuntu18.04
-            cmake_opts: -DKLOGG_USE_VECTORSCAN=OFF -DKLOGG_USE_HYPERSCAN=ON
+            container_root: docker/ubuntu20.04
+            container: variar/klogg_ubuntu20.04
+            cmake_opts:
 
 
     runs-on: ubuntu-22.04

docker/ubuntu18.04_qt5.15/Dockerfile renamed to docker/ubuntu20.04_qt5.15/Dockerfile

@@ -1,12 +1,12 @@
-FROM ubuntu:bionic
+FROM ubuntu:focal
 
 ENV DEBIAN_FRONTEND=noninteractive
 
 RUN apt-get update -y && \
     apt-get install --no-install-recommends software-properties-common -y && \
-    add-apt-repository ppa:beineri/opt-qt-5.15.2-bionic -y && \
+    add-apt-repository ppa:beineri/opt-qt-5.15.3-focal -y && \
     apt-get update -y && \
-    apt-get install --no-install-recommends build-essential python3 \
+    apt-get install --no-install-recommends build-essential python3 python-is-python3 \
                     qt515base qt515svg qt515tools qt515imageformats qt515translations \
                     mesa-common-dev libglu1-mesa-dev \
                     libboost-dev libicu-dev libssl-dev libcurl4-openssl-dev \