Update actions/checkout to v6 (#74)

* Update remove-icons-manually.yml

* Update sync-with-AM.yml

Author: ivan-hc

.github/workflows/remove-icons-manually.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: "Checkout source repository"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: "Remove unneeded icons"
         run: |

.github/workflows/sync-with-AM.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: "Checkout source repository"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: "Update lists"
         run: |