Bump actions/upload-artifact from 5 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/BitMono.Build.yaml

@@ -79,7 +79,7 @@ jobs:
           zip -qq -r ./BitMono-v${{ steps.project-build.outputs.version }}-CLI-${{ matrix.target-framework }}-${{ matrix.runtime }}.zip *
       
       - name: Upload build
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: BitMono-v${{ steps.project-build.outputs.version }}-CLI-${{ matrix.target-framework }}-${{ matrix.runtime }}
           path: "./src/BitMono.CLI/bin/Release/${{ matrix.target-framework }}/${{ matrix.runtime }}/BitMono-v${{ steps.project-build.outputs.version }}-CLI-${{ matrix.target-framework }}-${{ matrix.runtime }}.zip"
@@ -298,7 +298,7 @@ jobs:
           cd ..
       
       - name: Upload Unity Packages
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: BitMono-Unity-v${{ steps.cli-build.outputs.version }}-Unity${{ matrix.unity-version }}
           path: |