chore(ci): remove deprecated set-output syntax (#146)

fixes deprecation warnings in CI:
> The `set-output` command is deprecated and will be disabled soon.
Please upgrade to using Environment Files. For more information see:
https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Author: crccheck

.github/workflows/ci.yml

@@ -7,38 +7,35 @@ on:
       - master
 
 jobs:
-  create_matrix:
+  prepare:
     runs-on: ubuntu-latest
     steps:
       - name: Create matrix
-        uses: fabiocaccamo/create-matrix-action@v1
+        id: create_matrix
+        uses: fabiocaccamo/create-matrix-action@v3
         with:
           matrix: |
             python-version {3.7}, django-version {2.0,2.1,2.2,3.0,3.1}
             python-version {3.8}, django-version {2.2,3.0,3.1,3.2,4.0,4.1}
             python-version {3.9}, django-version {2.2,3.0,3.1,3.2,4.0,4.1}
             python-version {3.10}, django-version {3.2,4.0,4.1}
             python-version {3.11}, django-version {3.2,4.0,4.1}
-      - name: Set matrix output variable
-        id: set_matrix
-        run: |
-          echo "::set-output name=matrix::$(cat ./matrix.json)"
     outputs:
-      matrix: ${{ steps.set_matrix.outputs.matrix }}
+      matrix: ${{ steps.create_matrix.outputs.matrix }}
 
   test:
-    needs: create_matrix
+    needs: prepare
     strategy:
       fail-fast: false
       matrix:
-        include: ${{ fromJSON(needs.create_matrix.outputs.matrix) }}
+        include: ${{ fromJson(needs.prepare.outputs.matrix) }}
     name: "Python ${{ matrix.python-version }} + Django ${{ matrix.django-version }}"
     runs-on: ubuntu-latest
     env:
       POETRY_VIRTUALENVS_CREATE: false
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - run: pip install poetry
@@ -57,7 +54,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - name: Set up Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: "3.11"
       - run: pip install black