Increase workflow step versions (#52)

Increase checkout and setup-python to v4, Python 3.8 everywhere

Author: JackTemaki

.github/workflows/black.yml

@@ -10,8 +10,8 @@ jobs:
   check-black-formatting:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions/setup-python@v2
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v4
       with:
         python-version: 3.8
         cache: 'pip'

.github/workflows/model_tests.yml

@@ -10,11 +10,11 @@ jobs:
   test-jobs:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           repository: "rwth-i6/i6_models"
           path: ""
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v4
         with:
           python-version: 3.8
           cache: 'pip'

.github/workflows/publish.yml

@@ -17,11 +17,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v4
       with:
-        python-version: 3.7
+        python-version: 3.8
 
     - name: Install Python deps
       run: |