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](actions/upload-artifact@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] <support@github.com>

Author: dependabot[bot]

.github/workflows/push-nuget.yml

@@ -51,7 +51,7 @@ jobs:
       run: dotnet build --configuration ${{ env.build_configuration }} /p:Version=${{ env.VERSION }}
 
     - name: Upload build artifacts
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: library
         path: ${{ github.workspace }}/SteamStorefrontAPI/bin/${{ env.configuration }}
@@ -72,7 +72,7 @@ jobs:
         dotnet pack SteamStorefrontAPI --configuration ${{ env.build_configuration }} --no-build --output "${{ github.workspace }}/publish" /p:PackageVersion=${{ env.VERSION }}
 
     - name: Upload build artifacts
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: nuget
         path: ${{ github.workspace }}/publish