CI: Fix broken download of nightly build artifacts for Steam uploads

GitHub's CLI utility is not capable of downloading artifacts generated
by the workflow job it is being run in itself. Thus the official
repository action is needed.

.github/actions/steam-upload/action.yaml

@@ -68,6 +68,11 @@ runs:
         print "::error:steam-upload action can only be used with 'release', 'workflow-dispatch', or 'schedule' events."
         exit 2
 
+    - name: Download Nightly Assets 🌙
+      id: asset-info-nightly
+      uses: actions/download-artifact@v3
+      if: github.event_name == 'schedule'
+
     - name: Download Assets 📥
       id: asset-info
       shell: zsh --no-rcs --errexit --pipefail {0}
@@ -140,16 +145,12 @@ runs:
             }
             ;;
           schedule)
-            gh run download ${GITHUB_RUN_ID} \
-              --pattern '*macos*' \
-              --pattern '*windows*'
-
             local short_hash="${GITHUB_SHA:0:9}"
             mv obs-studio-windows-x64-${short_hash}/obs-studio-*-windows-x64.zip \
               ${root_dir}
             mv obs-studio-macos-arm64-${short_hash}/obs-studio-*-macos-apple.dmg \
               ${root_dir}
-            mv obs-studio-macos-intel-${short_hash}/obs-studio-*-macos-intel.dmg \
+            mv obs-studio-macos-x86_64-${short_hash}/obs-studio-*-macos-intel.dmg \
               ${root_dir}
 
             description="g${GITHUB_SHA}"