Fix: Resolve infinite recursion in keras.ops.associative_scan under Tensorflow static graph mode (#22072)

* Fixed issue #22058

* solved issue #22058

* issue #22058 fixed

* fixed issue #22058

* solved issue #22058

* modified code to handle <2 elem_length cases

* format corrected

* 'mutable' is explicitly set in nnx_metadata.

* reformatted

* formatted

* formatted

* formatted

* solved the error for imutable vars

* iterative approach

* reformats

* solved problems from review, removed dead code and used in-place mutation approach

* required changes and critical bugs solved. Writing tests remain

* reverted _direct_assign and _initialize, added tests

* Added tests for dynamic cases using tf.TensorSpec(shape=[None, ...])

* reformats

* used KerasTensor instead of tf.TensorSpec

* solved the 5 issues

* remaining fixes

* fixes in _interleave_with_b

* format fixes

* fixed crash issue

* format fixes