Upgrade Cyclegan to Keras 3 (with Tensorflow backend)

[pksX01]

This PR caters the upgradation of Cycelgan example to Keras 3 (with Tensorflow backend) from Keras 2.

Changes

• Since weight load format is changes in Keras 3, pre-trained weight could not be loaded. Hence, changed the epochs to 90 (as equivalent to original training).
• Replaced Tensorflow specific operations with Keras backend-agnostic equivalents wherever possible.

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[pksX01]

@sachinprasadhs could you please review this PR