Change image to ubuntu latest and container to python 3.7.

Author: runemalm

.github/workflows/feature.yml

@@ -8,7 +8,8 @@ on:
 jobs:
   pre-commit:
     name: Run pre-commit
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
+    container: python:3.7
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -23,7 +24,8 @@ jobs:
 
   unittests:
     name: Run tests
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
+    container: python:3.7
 
     strategy:
       matrix:

.github/workflows/master.yml

@@ -9,7 +9,8 @@ on:
 jobs:
   pre-commit:
     name: Run pre-commit
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
+    container: python:3.7
 
     steps:
       - name: Checkout code
@@ -25,7 +26,8 @@ jobs:
 
   unittests:
     name: Run unittests
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
+    container: python:3.7
 
     strategy:
       matrix:
@@ -45,7 +47,8 @@ jobs:
     name: Pre-release (test-pypi)
     needs: unittests
     if: success()
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
+    container: python:3.7
 
     steps:
       - name: Checkout code
@@ -72,7 +75,8 @@ jobs:
     name: Release (pypi)
     needs: prerelease
     if: success() && (github.event_name == 'workflow_dispatch')
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
+    container: python:3.7
 
     steps:
       - name: Download artifact