Update GitHub actions to latest generation (v4)

Author: AbandonedCart

.github/workflows/android.yml

@@ -75,7 +75,7 @@ jobs:
         # override default build-tools version (29.0.3) -- optional
         BUILD_TOOLS_VERSION: "34.0.0"
 
-    - uses: actions/upload-artifact@v3
+    - uses: actions/upload-artifact@v4
       with:
         name: Signal-Android-${{ env.GIT_HASH }}
         retention-days: 1
@@ -101,4 +101,4 @@ jobs:
       uses: MyAlbum/purge-cache@v2
       with:
         max-age: 172800 # 1 day, default: 7 days since last use
-        token: ${{ secrets.GITHUB_TOKEN }}
+        token: ${{ secrets.GITHUB_TOKEN }}