Remove GH Action on push (#27)

only PR are authorized

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*Description of changes:*


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Author: sebsto

.github/workflows/pull_request.yml

@@ -3,8 +3,6 @@
 name: swift-openapi-lambda-build
 
 on:
-  push:
-    branches: ["main"]
   pull_request:
     types: [opened, reopened, synchronize]
 
@@ -53,4 +51,4 @@ jobs:
         with:
           persist-credentials: false
       - name: Check for Semantic Version label
-        uses: apple/swift-nio/.github/actions/pull_request_semver_label_checker@main
+        uses: apple/swift-nio/.github/actions/pull_request_semver_label_checker@main