[Obs AI Assistant] Remove double confirmation when deleting conversation (#217991)

Closes https://github.com/elastic/kibana/issues/213987

## Summary

Remove the checkbox from the confirm modal to avoid double confirmation.

### Before

<img width="475" alt="Screenshot 2025-04-11 at 11 56 54"
src="https://github.com/user-attachments/assets/6b24aa8a-06b8-4f97-b43d-a82e91ce8328"
/>

### After

<img width="580" alt="Screenshot 2025-04-11 at 11 07 19"
src="https://github.com/user-attachments/assets/91965922-8b66-473a-903c-c6d14e2ee49e"
/>

### Checklist

- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

x-pack/platform/packages/shared/kbn-ai-assistant/src/chat/chat_context_menu.tsx

@@ -129,12 +129,7 @@ export function ChatContextMenu({
         `}
         icon={<EuiIcon type="trash" size="m" color="danger" />}
         onClick={() => {
-          confirmDeleteCallback(
-            i18n.translate('xpack.aiAssistant.flyout.confirmDeleteCheckboxLabel', {
-              defaultMessage: 'Delete "{title}"',
-              values: { title: conversationTitle },
-            })
-          ).then((confirmed) => {
+          confirmDeleteCallback().then((confirmed) => {
             if (!confirmed) {
               return;
             }

x-pack/platform/packages/shared/kbn-ai-assistant/src/chat/conversation_list.tsx

@@ -185,12 +185,7 @@ export function ConversationList({
                     currentUser,
                   }),
                   onClick: () => {
-                    confirmDeleteCallback(
-                      i18n.translate('xpack.aiAssistant.flyout.confirmDeleteCheckboxLabel', {
-                        defaultMessage: 'Delete "{title}"',
-                        values: { title: conversation.label },
-                      })
-                    ).then((confirmed) => {
+                    confirmDeleteCallback().then((confirmed) => {
                       if (!confirmed) return;
                       deleteConversation(conversation.id).then(() => {
                         if (conversation.id === selectedConversationId) {

x-pack/platform/packages/shared/kbn-ai-assistant/src/hooks/use_confirm_modal.tsx

@@ -6,27 +6,22 @@
  */
 
 import React from 'react';
-import { EuiCheckbox, EuiConfirmModal, EuiText } from '@elastic/eui';
+import { EuiConfirmModal, EuiText } from '@elastic/eui';
 import { useState } from 'react';
-import { css } from '@emotion/css';
 
 const ConfirmModal = ({
-  checkboxLabel,
   onClose,
   title,
   children,
   confirmButtonText,
   setElement,
 }: {
-  checkboxLabel: string;
   onClose: (confirmed: boolean) => void;
   title: React.ReactNode;
   children: React.ReactNode;
   confirmButtonText: React.ReactNode;
   setElement: (element: React.ReactNode | undefined) => void;
 }) => {
-  const [isChecked, setIsChecked] = useState(false);
-
   return (
     <EuiConfirmModal
       title={title}
@@ -41,19 +36,9 @@ const ConfirmModal = ({
       confirmButtonText={confirmButtonText}
       cancelButtonText="Cancel"
       buttonColor="danger"
-      confirmButtonDisabled={!isChecked}
       maxWidth
     >
       <EuiText>{children}</EuiText>
-      <EuiCheckbox
-        id="deleteConfirmationCheckbox"
-        label={checkboxLabel}
-        checked={isChecked}
-        onChange={(e) => setIsChecked(e.target.checked)}
-        className={css`
-          margin-top: 15px;
-        `}
-      />
     </EuiConfirmModal>
   );
 };
@@ -68,16 +53,15 @@ export function useConfirmModal({
   confirmButtonText: React.ReactNode;
 }): {
   element: React.ReactNode | undefined;
-  confirm: (checkBoxLabel: string) => Promise<boolean>;
+  confirm: () => Promise<boolean>;
 } {
   const [element, setElement] = useState<React.ReactNode | undefined>(undefined);
 
-  const confirm = (checkboxLabel: string) => {
+  const confirm = () => {
     return new Promise<boolean>((resolve) => {
       setElement(() => {
         return (
           <ConfirmModal
-            checkboxLabel={checkboxLabel}
             onClose={resolve}
             title={title}
             children={children}