Automated Resyntax fixes

* Fix 1 occurrence of `if-let-to-cond`

`cond` with internal definitions is preferred over `if` with `let`, to reduce nesting

* Fix 1 occurrence of `explicit-cond-else-void`

Add an explicit `[else (void)]` clause to make the default behavior clear.

* Fix 3 occurrences of `printf-to-display`

This use of `printf` has no arguments other than the template string.

* Fix 3 occurrences of `let-to-define`

Internal definitions are recommended instead of `let` expressions, to reduce nesting.

* Fix 1 occurrence of `cond-let-to-cond-define`

Internal definitions are recommended instead of `let` expressions, to reduce nesting.

* Fix 4 occurrences of `map-to-for`

This `map` operation can be replaced with a `for/list` loop.

* Fix 5 occurrences of `define-lambda-to-define`

The `define` form supports a shorthand for defining functions.

* Fix 1 occurrence of `arrow-contract-with-rest-to-arrow-contract-with-ellipses`

This `->*` contract can be rewritten using `->` with ellipses.

* Fix 1 occurrence of `provide/contract-to-contract-out`

The `provide/contract` form is a legacy form made obsolete by `contract-out`.

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Co-authored-by: resyntax-ci[bot] <181813515+resyntax-ci[bot]@users.noreply.github.com>

Author: resyntax-ci[bot]