PG-375: only run code coverage test on merge

Signed-off-by: Kai Wagner <kai.wagner@percona.com>

.github/workflows/coverage_test.yml

@@ -1,7 +1,12 @@
-name: coverage-test
-on: ["push", "pull_request"]
+name: coverage_test
+on:
+  pull_request:
+    types:
+      - closed 
 
 jobs:
+  if_merged:
+    if: github.event.pull_request.merged == true
     build:
     name: coverage-test
     runs-on: ubuntu-latest

.github/workflows/postgresql-14-build.yml

@@ -1,5 +1,5 @@
 name: postgresql-14-build
-on: [push]
+on: ["push", "pull_request"]
 
 jobs:
   build: