GitHub Actions ci.yml: update runners, run on all branches

Author: greenrobot

.github/workflows/ci.yml

@@ -3,7 +3,6 @@ name: CI
 # Avoid duplicate builds for pull requests, allow manual trigger.
 on:
   push:
-    branches: [ main ]
   pull_request:
   workflow_dispatch:
 
@@ -15,10 +14,8 @@ jobs:
   build:
     strategy:
       matrix:
-        os:
-          - windows-2019
-          - macos-12
-          - ubuntu-22.04
+        # Available runners: https://docs.github.com/en/actions/reference/runners/github-hosted-runners
+        os: [ ubuntu-latest, macos-latest, macos-26, windows-latest ]
     runs-on: ${{ matrix.os }}
     steps:
       - run: git config --global core.autocrlf false