Store requirements as build artifact.

Author: tillahoffmann

.github/workflows/requirements.yml

@@ -28,3 +28,8 @@ jobs:
         run: |
           rm requirements/${{ matrix.python-version }}.txt
           pip-compile --resolver=backtracking -v --upgrade -o requirements/${{ matrix.python-version }}.txt
+      - name: Store requirements as artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: requirements/${{ matrix.python-version }}.txt
+          path: requirements/${{ matrix.python-version }}.txt