Bump actions/upload-artifact from 6 to 7 (#790)

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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/osxbinary.yml

@@ -31,7 +31,7 @@ jobs:
       - run: make
       - run: sudo make install
       - run: make osx-dmg
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           name: artifact-osx-14
           path: "*.dmg"

.github/workflows/tools.yml

@@ -68,7 +68,7 @@ jobs:
           cp gambit* installer
           "${WIX}bin/candle" build_support/msw/gambit.wxs
           "${WIX}bin/light" -ext WixUIExtension gambit.wixobj
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           name: artifact-msw
           path: "*.msi"

.github/workflows/wheels.yml

@@ -27,6 +27,6 @@ jobs:
           python -m cibuildwheel --output-dir wheelhouse/
         env:
           CIBW_SKIP: "pp*"
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           path: ./wheelhouse/*.whl