fix(prefer-array-at): guard against more assignment cases where .at(-1) would be illegal

[TkDodo]

This PR makes the prefer-array-at rule more resilient to assignment cases:

1. left-hand assignments
   like items[items.length - 1]! = 42 or items[items.length - 1]! += 42 are no longer transformed because they would lead to TS2364. Note that type assertions and non-null assertions no the target side needed explicit checking. This is what was reported in prefer-array-at produces invalid code: #148, normal assignments without ! were already properly checked.

2. for-in and for-of assignments
   while uncommon, can lead to Uncaught ReferenceError: Invalid left-hand side in for-loop

3. Destructuring
   also uncommon, but can lead to Uncaught SyntaxError: Invalid destructuring assignment target

4. delete
   transforming delete items[items.length - 1] into delete items.at(-1) yields no runtime error, but doesn’t delete anything and is therefore wrong.

fixes #148

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Note: This PR was created with the help of AI, but a human (me) was always in the loop and no communication was done using AI. I am not a meat proxy.