chore: bump local dev redis image to redis:8

Redis 8 GA'd 2025-05 (back to OSI-approved AGPLv3 licensing) and ships
RedisJSON / RediSearch / RedisTimeSeries / RedisBloom in-tree.

No Symfony / phpredis changes needed:
- symfony/cache 6.4 RedisTrait only checks `redis_version >= 2.8` (SCAN)
  and `>= 4.0` (UNLINK); Redis 8 satisfies both.
- itkdev/php8.4-fpm ships phpredis 6.3, which fully supports Redis 8.
- DSN format and `--maxmemory{,-policy}` flags are unchanged.

Verified locally: stack boots on `redis:8.6.3`, all six redis-backed
cache pools clear cleanly via `cache:pool:clear`, full PHPUnit suite
(143 tests, 607 assertions) passes.

Production deployments are unaffected — operators bring their own Redis;
this only touches `docker-compose.override.yml`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: turegjorup

CHANGELOG.md

@@ -10,6 +10,8 @@ All notable changes to this project will be documented in this file.
 - Aligned API and Nginx image labels with the OCI image spec: dropped deprecated `LABEL maintainer`,
   added `org.opencontainers.image.{authors,vendor,documentation,base.name}`, and fixed the Nginx image's
   `title`/`description` so it stops inheriting the source-repo defaults.
+- Bumped the local dev Redis image from `redis:6` to `redis:8`. Production deployments are unaffected
+  (they bring their own Redis); Symfony 6.4's cache adapter and the bundled phpredis 6.3 work as-is.
 
 ## [3.0.0-rc2] - 2026-05-05
 

docker-compose.override.yml

@@ -6,7 +6,12 @@ services:
       - "traefik.http.middlewares.redirect-to-https.redirectscheme.scheme=https"
 
   redis:
-    image: "redis:6"
+    # Redis 8 GA'd 2025-05; back to OSI-approved licensing (AGPLv3) and
+    # ships RedisJSON / RediSearch / RedisTimeSeries / RedisBloom in-tree.
+    # Symfony 6.4 cache adapter only checks `redis_version >= 4.0`; the
+    # phpredis 6.3 shipped in itkdev/php8.4-fpm supports the new RESP3
+    # niceties without any code change here.
+    image: "redis:8"
     command: redis-server --maxmemory 128mb --maxmemory-policy allkeys-lru
     networks:
       - app