fix(lambda/function): resource is ready when function is inactive due to idle

[wotolom]

Description of your changes

for Function.lambda:

• set MR to Ready: True when Function is in state: Inactive when stateReason: Idle (AWS sets Function to Idle after 14 days: https://docs.aws.amazon.com/lambda/latest/dg/snapstart-activate.html#snapstart-function-states)
• for all other cases keep setting MR to Ready: False when Function is in state: Inactive

with previous/current behavior the resource is set to Ready: False when idle
The previous/current handling differs from the way Upbound Function.lambda behaves. This change aims to adapt this.

I have:

• Read and followed Crossplane's [contribution process].
• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

manually

[MisterMX]

LGTM. Thank you very much @wotolom!

[github-actions]

Successfully created backport PR #2085 for release-0.49.