Add Python 3.13 support with uuid7 backport compatibility

- Create uuid_compat.py module that provides uuid7 for Python <3.14
  using uuid_extensions package, and native uuid.uuid7 for Python 3.14+
- Update all model files and migrations to use archivebox.uuid_compat
- Add uuid7 conditional dependency in pyproject.toml for Python <3.14
- Update requires-python to >=3.13 (from >=3.14)
- Update GitHub workflows, lock_pkgs.sh to use Python 3.13
- Update tool configs (ruff, pyright, uv) for Python 3.13

This enables running ArchiveBox on Python 3.13 while maintaining
forward compatibility with Python 3.14's native uuid7 support.

archivebox/api/migrations/0002_alter_outboundwebhook_options_and_more.py

@@ -3,7 +3,7 @@
 import django.utils.timezone
 import signal_webhooks.fields
 import signal_webhooks.utils
-import uuid
+from archivebox import uuid_compat
 from django.conf import settings
 from django.db import migrations, models
 
@@ -39,7 +39,7 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='apitoken',
             name='id',
-            field=models.UUIDField(default=uuid.uuid7, editable=False, primary_key=True, serialize=False, unique=True),
+            field=models.UUIDField(default=uuid_compat.uuid7, editable=False, primary_key=True, serialize=False, unique=True),
         ),
         migrations.AlterField(
             model_name='outboundwebhook',
@@ -69,7 +69,7 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='outboundwebhook',
             name='id',
-            field=models.UUIDField(default=uuid.uuid7, editable=False, primary_key=True, serialize=False, unique=True),
+            field=models.UUIDField(default=uuid_compat.uuid7, editable=False, primary_key=True, serialize=False, unique=True),
         ),
         migrations.AlterField(
             model_name='outboundwebhook',