fix(redis): Resolve DeleteMany failure by supporting regex matching and optimizing deletion

[IndraGunawan]

Problem

Initially, calling the /flush endpoint on the Souin API did not clear data in Redis. This happened because the API passes .+ (https://github.com/darkweak/souin/blob/master/pkg/api/souin.go#L313) to DeleteMany, but the Redis only supports glob patterns. Consequently, .+ would not match any keys in Redis.

Solution

To resolve the pattern mismatch, I've updated the logic to perform a full scan of keys and filter them locally using Go's regexp packagem, like what go-redis does. This ensures that any regex pattern passed by the upstream caller is correctly applied.

Improvements

• Optimized Scanning: Integrated the Count parameter into the SCAN command to minimize network roundtrips during key discovery.
• Non-blocking Batch Deletion: Replaced the blocking DEL command with UNLINK and modified the flow to send the unlink command immediately after each scan iteration. This prevents blocking the Redis server and avoids building a massive slice of keys in memory.

[darkweak]

Thanks @IndraGunawan for this PR. Can we replicate these benefits in the go-redis package aswell?

[IndraGunawan]

Thanks @IndraGunawan for this PR. Can we replicate these benefits in the go-redis package aswell?

Yes, just pushed the implementation