[ci]: Enable daily building for ubuntu20.04 to every branch (#17520)

- The ubuntu 2004 is needed by 202311
- Because the artifacts of ubuntu2004 are used by other repos, a daily building is needed without an updating of this repo for a long time.

Signed-off-by: Ze Gan <ganze718@gmail.com>

.azure-pipelines/azure-pipelines-build-ubuntu-2004.yml

@@ -9,6 +9,16 @@ trigger:
   branches:
     include:
     - master
+    - 202???
+
+schedules:
+- cron: "0 0 * * *"
+  displayName: Daily build
+  branches:
+    include:
+      - master
+      - 202???
+  always: true
 
 stages:
 - stage: Build