Bump coactions/matrix from 3 to 4 (#172)

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

Author: dependabot[bot]

.github/workflows/tox.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - name: Determine matrix
         id: generate_matrix
-        uses: coactions/matrix@v3
+        uses: coactions/matrix@v4
         with:
           other_names: |
             lint