remove keyboard auth callback and use generic auth callback

[JacobBarthelmeh]

ZD19766

Note that this brakes backwards compatibility with the keyboard auth callbacks. Moving it over to use the generic auth callback framework.

[Copilot]

Pull Request Overview

This PR removes the keyboard interactive authentication callback functions and integrates keyboard auth into the generic user authentication callback.

• Removed deprecated keyboard auth callback declarations and functions.
• Introduced a new auth type macro (WOLFSSH_USERAUTH_KEYBOARD_SETUP) and updated logic across internal and example files to use the generic auth callback instead.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
wolfssh/ssh.h	Removed keyboard auth callback declarations and added new macro.
wolfssh/internal.h	Removed keyboard auth callback member from the context struct.
src/ssh.c	Removed keyboard-specific functions; updated keyboard auth request to use generic callback.
src/internal.c	Updated keyboard auth request handling to use userAuthCb and modified auth type usage.
examples/echoserver/echoserver.c	Adjusted example usage accordingly by removing calls to deprecated functions.

Comments suppressed due to low confidence (1)

src/ssh.c:13379

• There is a mismatch between the authData type being set (WOLFSSH_USERAUTH_KEYBOARD) and the callback parameter (WOLFSSH_USERAUTH_KEYBOARD_SETUP) passed to userAuthCb. Consider aligning these values for consistent behavior.

authData->type = WOLFSSH_USERAUTH_KEYBOARD;