ci: run CI workflow on any submitted pull request

Author: jdaugherty

.github/workflows/gradle.yml

@@ -17,12 +17,8 @@ name: "CI"
 on:
   push:
     branches:
-      - '[4-9]+.[0-9]+.x'
-      - '[3-9]+.[3-9]+.x'
+      - '[0-9]+.[0-9]+.x'
   pull_request:
-    branches:
-      - '[4-9]+.[0-9]+.x'
-      - '[3-9]+.[3-9]+.x'
   workflow_dispatch:
 # queue jobs and only allow 1 run per branch due to the likelihood of hitting GitHub resource limits
 concurrency: