Bump actions/upload-artifact from 4 to 5 (#1970)

Author: dependabot[bot]

.github/workflows/caldav-test.yml

@@ -56,7 +56,7 @@ jobs:
           meson test -C build --suite=caldav-integration --print-errorlogs
 
       - name: Upload Meson test log
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: meson-test-log
           path: build/meson-logs/testlog.txt