Add deleteByValue to circular linked list and expose in CLI menu

[Nullkernel]

Motivation

• Provide a safe deleteByValue operation for the circular linked list that handles common edge cases and makes value-based deletion available from the interactive menu.
• Ensure deletions correctly maintain the circular list invariants (especially tail and tail.next) and avoid infinite loops when the key is absent.

Description

• Added public void deleteByValue(int key) to Data-Structures/Linked-Lists/CircularLinkedLists.java with handling for tail == null, single-node circles, deleting the tail (updates tail), deleting the head (updates tail.next), and stopping after one full cycle when the key is not found.
• Wired the new operation into the CLI: added menu option 5. Delete by Value, shifted subsequent options, and changed the exit choice from 7 to 8 accordingly.
• Updated the switch in main to read the delete key from the user and call deleteByValue, and added a sample output block demonstrating insertion, delete-by-value, and display.

Testing

• Compiled the modified file with javac Data-Structures/Linked-Lists/CircularLinkedLists.java and the compilation succeeded.

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Codex Task