[core] Error check Redis get requests

[vitsai]

It is possible for a Redis Get to silently fail in the current logic. Fix this to avoid weird downstream effects (such as session key inconsistency)

Why are these changes needed?

Related issue number

#40412

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[fishbone]

Synced offline. It seems that we have already crashed the program when receiving an error here

So the error might come from Connect here

Some simple test without Redis can verify this.

[fishbone]

LG!