fix repo string

Author: goergisn

action.yml

@@ -15,7 +15,7 @@ runs:
     steps:
     - uses: actions/checkout@v4
       with:
-        repository: "https://github.com/Adyen/adyen-swift-public-api-diff"
+        repository: "Adyen/adyen-swift-public-api-diff"
         ref: "main"
     - name: "Run Diff"
       run: |