[Dev] [fix] Bug fix for fine-grained activation offloading in evaluate()

[lhb8125]

What does this PR do ?

PR for main
Return None when the forward offloading chunk handlers are used up, which could occur in evaluate(), where only forward pass is executed.

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[lhb8125]

/ok to test 0bcdf9c

[lhb8125]

/ok to test 16ca9e8