build: stop supporting Ubuntu 20.04

Author: homuler

docker/linux/x86_64/Dockerfile

@@ -3,7 +3,7 @@ ARG ANDROID_SDK_BUILD_TOOLS_VERSION=30.0.3
 ARG ANDROID_SDK_VERSION=30
 ARG ANDROID_NDK_VERSION=21.4.7075529
 
-FROM ubuntu:20.04 AS base
+FROM ubuntu:22.04 AS base
 
 ENV DEBIAN_FRONTEND=noninteractive