Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/release.yml

@@ -88,13 +88,13 @@ jobs:
           zip -r -q offline.zip site
 
       - name: Upload tar.gz file
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: offline.tar.gz
           path: offline.tar.gz
 
       - name: Upload zip file
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: offline.zip
           path: offline.zip
@@ -108,7 +108,7 @@ jobs:
             zimwriterfs -w index.html -I assets/brand/PNG/Square/pg-yellow.png -l eng -t "Privacy Guides" -d "Your central privacy and security resource to protect yourself online." -c "Privacy Guides" -p "Jonah Aragon" -n "Privacy Guides" -e "https://github.com/privacyguides/privacyguides.org" /data/site /data/privacy_guides.zim
       
       - name: Upload ZIM file
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: privacy_guides.zim
           path: privacy_guides.zim