ICU-21473 Enable GHA CI on maint/maint* branches
diff --git a/.github/workflows/icu_ci.yml b/.github/workflows/icu_ci.yml
index 2bdb0a8..58bf4fa 100644
--- a/.github/workflows/icu_ci.yml
+++ b/.github/workflows/icu_ci.yml
@@ -7,9 +7,11 @@
 
 on:
   push:
-    branches: [ master ]
+    branches:
+      - master
+      - 'maint/maint*'
   pull_request:
-    branches: '*'
+    branches: '**'
 
 jobs: