CI trigger test runs on pull requests events (#3591)

.github/workflows/buf-binary-size.yaml

@@ -1,5 +1,9 @@
 name: binary-size
-on: push
+on:
+  push:
+    branches:
+      - main
+  pull_request:
 # Prevent writing to the repository using the CI token.
 # Ref: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#permissions
 permissions: read-all

.github/workflows/ci.yaml

@@ -1,5 +1,9 @@
 name: ci
-on: push
+on:
+  push:
+    branches:
+      - main
+  pull_request:
 # Prevent writing to the repository using the CI token.
 # Ref: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#permissions
 permissions: read-all

.github/workflows/previous.yaml

@@ -1,5 +1,9 @@
 name: previous
-on: push
+on:
+  push:
+    branches:
+      - main
+  pull_request:
 # Prevent writing to the repository using the CI token.
 # Ref: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#permissions
 permissions: read-all

.github/workflows/windows.yaml

@@ -1,5 +1,9 @@
 name: windows
-on: push
+on:
+  push:
+    branches:
+      - main
+  pull_request:
 # Prevent writing to the repository using the CI token.
 # Ref: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#permissions
 permissions: read-all