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](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/ci.yml

@@ -64,7 +64,7 @@ jobs:
 
       - name: Upload coverage data
         if: matrix.session == 'unit' && matrix.python == '3.13' && matrix.os == 'ubuntu-latest'
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: coverage-data
           path: .coverage

.github/workflows/publish.yml

@@ -37,7 +37,7 @@ jobs:
           manylinux: auto
 
       - name: Upload wheels
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: wheels-linux-${{ matrix.platform.target }}
           path: dist
@@ -68,7 +68,7 @@ jobs:
           sccache: "true"
 
       - name: Upload wheels
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: wheels-macos-${{ matrix.platform.target }}
           path: dist
@@ -98,7 +98,7 @@ jobs:
           sccache: "true"
 
       - name: Upload wheels
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: wheels-windows-${{ matrix.platform.target }}
           path: dist
@@ -116,7 +116,7 @@ jobs:
           args: --out dist
 
       - name: Upload sdist
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: wheels-sdist
           path: dist