[NO-TICKET] Update redis container to redis 8

[vpellan]

What does this PR do?

This PR update redis container to redis 8, and activate Sidekiq tests.

Motivation:

Sidekiq tests are failing locally (in container environment) as it requires redis 7 at least.

Change log entry

none.

Additional Notes:

How to test the change?

CI / locally, in container, using bundle exec rake test:sidekiq

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-07-16 12:05:06

Comparing candidate commit 4696a6f in PR branch vpellan/update-redis-to-8 with baseline commit 633b084 in branch master.

Found 1 performance improvements and 1 performance regressions! Performance is the same for 42 metrics, 5 unstable metrics.

scenario:error - error tracking with http - third_party only

• 🟥 throughput [-86.277op/s; -72.287op/s] or [-60.652%; -50.818%]

scenario:tracing - trace.to_digest

• 🟩 throughput [+7586.046op/s; +8117.134op/s] or [+5.559%; +5.949%]