Bump actions/upload-artifact from 3 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/ch07-packaging.yml

@@ -96,7 +96,7 @@ jobs:
         run: python -m build --sdist
         working-directory: ch07/first-python-package # You don't need this in your package
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v6
         with:
           path: ch07/first-python-package/dist/*.tar.gz
 
@@ -121,7 +121,7 @@ jobs:
         run: python -m cibuildwheel --output-dir wheels
         working-directory: ch07/first-python-package # You don't need this in your package
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v6
         with:
           path: ./ch07/first-python-package/wheels/*.whl # Update to match root of package
 

.github/workflows/ch08-packaging.yml

@@ -96,7 +96,7 @@ jobs:
         run: python -m build --sdist
         working-directory: ch08/first-python-package # You don't need this in your package
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v6
         with:
           path: ch08/first-python-package/dist/*.tar.gz
 
@@ -121,7 +121,7 @@ jobs:
         run: python -m cibuildwheel --output-dir wheels
         working-directory: ch08/first-python-package # You don't need this in your package
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v6
         with:
           path: ./ch08/first-python-package/wheels/*.whl # Update to match root of package