Fix returning logged metrics instead of callback metrics during evaluation

[rohitgr7]

What does this PR do?

With

self.log(..., on_step=True, on_epoch=True

the results returned were:

│        valid_loss         │            3.0            │
│     valid_loss_epoch      │            3.0            │
└───────────────────────────┴──────────────────────────

should be just logged metrics instead.

Does your PR introduce any breaking changes? If yes, please list them.

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cc @Borda @carmocca @edward-io @ananthsub @rohitgr7 @kamil-kaczmarek @Raalsky @Blaizzy

[tchaton]

Nice catch !