ci: bump actions/upload-artifact from 6 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/windows-build.yml

@@ -222,7 +222,7 @@ jobs:
 
       - name: Upload Installer
         id: upload_installer
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: Installer ${{ matrix.arch }}
           path: ZoiteChat-*.exe
@@ -236,7 +236,7 @@ jobs:
 
       - name: Upload Build Files
         id: upload_buildfiles
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: Build Files ${{ matrix.arch }}
           path: zoitechat-build