(chore): Bump upload-artifact and download-artifact to v4 (#395)

Author: jonathanedey

.github/workflows/nightly.yml

@@ -66,7 +66,7 @@ jobs:
     # Attach the packaged artifacts to the workflow output. These can be manually
     # downloaded for later inspection if necessary.
     - name: Archive artifacts
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v4
       with:
         name: Release
         path: FirebaseAdmin/FirebaseAdmin/bin/Release

.github/workflows/release.yml

@@ -77,7 +77,7 @@ jobs:
     # Attach the packaged artifacts to the workflow output. These can be manually
     # downloaded for later inspection if necessary.
     - name: Archive artifacts
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v4
       with:
         name: Release
         path: FirebaseAdmin/FirebaseAdmin/bin/Release
@@ -105,7 +105,7 @@ jobs:
 
     # Download the artifacts created by the stage_release job.
     - name: Download release candidates
-      uses: actions/download-artifact@v1
+      uses: actions/download-artifact@v4
       with:
         name: Release