ci: Update Python to 3.8

.github/workflows/build.yml

@@ -5,10 +5,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: Set up Python 3.7
+    - name: Set up Python 3.8
       uses: actions/setup-python@v5
       with:
-        python-version: '3.7'
+        python-version: '3.8'
     - name: Install flake8
       run: pip install flake8 flake8-import-order flake8-future-import flake8-commas flake8-logging-format flake8-quotes
     - name: Lint with flake8
@@ -19,10 +19,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: Set up Python 3.7
+    - name: Set up Python 3.8
       uses: actions/setup-python@v5
       with:
-        python-version: '3.7'
+        python-version: '3.8'
     - name: Cache pip
       uses: actions/cache@v4
       with:

.github/workflows/compilemessages.yml

@@ -11,10 +11,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: Set up Python 3.7
+    - name: Set up Python 3.8
       uses: actions/setup-python@v5
       with:
-        python-version: '3.7'
+        python-version: '3.8'
     - name: Checkout submodules
       run: |
         git submodule init

.github/workflows/makemessages.yml

@@ -8,10 +8,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: Set up Python 3.7
+    - name: Set up Python 3.8
       uses: actions/setup-python@v5
       with:
-        python-version: '3.7'
+        python-version: '3.8'
     - name: Checkout submodules
       run: |
         git submodule init

.github/workflows/updatemessages.yml

@@ -10,10 +10,10 @@ jobs:
     - uses: actions/checkout@v4
       with:
         fetch-depth: 0
-    - name: Set up Python 3.7
+    - name: Set up Python 3.8
       uses: actions/setup-python@v5
       with:
-        python-version: '3.7'
+        python-version: '3.8'
     - name: Checkout submodules
       run: |
         git submodule init

judge/admin/submission.py

@@ -82,7 +82,7 @@ def formfield_for_dbfield(self, db_field, **kwargs):
                                                                          contest__problems=submission.problem) \
                     .only('id', 'contest__name', 'virtual')
 
-                def label(obj):
+                def label(obj):  # noqa: F811
                     if obj.spectate:
                         return gettext('%s (spectating)') % obj.contest.name
                     if obj.virtual:
@@ -92,7 +92,7 @@ def label(obj):
                 kwargs['queryset'] = ContestProblem.objects.filter(problem=submission.problem) \
                     .only('id', 'problem__name', 'contest__name')
 
-                def label(obj):
+                def label(obj):  # noqa: F811
                     return pgettext('contest problem', '%(problem)s in %(contest)s') % {
                         'problem': obj.problem.name, 'contest': obj.contest.name,
                     }