🔧(backend) fix Redis dependency conflict by downgrading to v5.2.1

Resolve ResolutionImpossible error where meet requires redis==6.2.0
but kombu[redis] 5.5.x requires redis<=5.2.1. Downgrade to redis==5.2.1
satisfies overlapping constraints and testing confirms compatibility.

Pin the redis dependency.

renovate.json

@@ -7,7 +7,7 @@
       "enabled": false,
       "groupName": "ignored python dependencies",
       "matchManagers": ["pep621"],
-      "matchPackageNames": []
+      "matchPackageNames": ["redis"]
     },
     {
       "enabled": false,

src/backend/pyproject.toml

@@ -34,7 +34,7 @@ dependencies = [
     "django-countries==7.6.1",
     "django-lasuite==0.0.10",
     "django-parler==2.3",
-    "redis==6.2.0",
+    "redis==5.2.1",
     "django-redis==6.0.0",
     "django-storages[s3]==1.14.6",
     "django-timezone-field>=5.1",

src/summary/pyproject.toml

@@ -8,7 +8,7 @@ dependencies = [
     "pydantic>=2.5.0",
     "pydantic-settings>=2.1.0",
     "celery==5.5.3",
-    "redis==6.2.0",
+    "redis==5.2.1",
     "minio==7.2.15",
     "openai==1.91.0",
     "requests==2.32.4",