CI: update GHA jobs

Author: Tinche

.github/workflows/pypi-package.yml

@@ -24,7 +24,7 @@ jobs:
         with:
           fetch-depth: 0
 
-      - uses: hynek/build-and-inspect-python-package@v1
+      - uses: hynek/build-and-inspect-python-package@v2
 
   # Upload to Test PyPI on every commit on main.
   release-test-pypi:
@@ -36,7 +36,7 @@ jobs:
 
     steps:
       - name: Download packages built by build-and-inspect-python-package
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: Packages
           path: dist
@@ -56,7 +56,7 @@ jobs:
 
     steps:
       - name: Download packages built by build-and-inspect-python-package
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: Packages
           path: dist