add 1.21.4.3 to matrix

Author: chronolaw

.github/workflows/build_and_test_with_resty_events.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        openresty-version: [1.19.9.1, 1.21.4.1, 1.25.3.1]
+        openresty-version: [1.19.9.1, 1.21.4.1, 1.21.4.3, 1.25.3.1]
 
     steps:
       - name: Update and install OS dependencies