Upgrade GitHub Actions for Node 24 compatibility (#300)

Signed-off-by: Salman Muin Kayser Chishti <13schishti@gmail.com>

Author: salmanmkc

.github/workflows/ci.yml

@@ -26,14 +26,14 @@ jobs:
         steps:
             - name: Checkout PR merge ref if called from PR
               if: ${{ github.event.pull_request.number }}
-              uses: actions/checkout@v4
+              uses: actions/checkout@v6
               with:
                   ref: refs/pull/${{ github.event.pull_request.number }}/merge
                   fetch-depth: 0
 
             - name: Checkout fallback
               if: ${{ !github.event.pull_request.number }}
-              uses: actions/checkout@v4
+              uses: actions/checkout@v6
 
             - run: |
                   swift format lint --strict --recursive .