MM-53813: Fix(accessibility): on channels page (#24122)

* fix(accessibility): on channels page

* fix lint and update dynamic-virtualized-list

* fix snapshot and update per feedback

* fix e2e tests

* fix test

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/cypress/tests/integration/channels/accessibility/accessibility_keyboard_usability_spec.js

@@ -137,10 +137,11 @@ describe('Verify Accessibility keyboard usability across different regions in th
             cy.clickPostCommentIcon(postId);
 
             // * Verify Screen reader should not switch to virtual cursor mode. This is handled by adding a role=application attribute
-            const regions = ['#sidebar-left', '#rhsContainer .post-right__content', '.search__form', '#advancedTextEditorCell'];
+            const regions = ['#sidebar-left', '#rhsContainer .post-right__content', '#advancedTextEditorCell'];
             regions.forEach((region) => {
                 cy.get(region).should('have.attr', 'role', 'application');
             });
+            cy.get('.search__form').should('have.attr', 'role', 'search');
             cy.get(`#post_${postId}`).children('.post__content').eq(0).should('have.attr', 'role', 'application');
             cy.get(`#rhsPost_${postId}`).children('.post__content').eq(0).should('have.attr', 'role', 'application');
         });

e2e-tests/cypress/tests/integration/channels/accessibility/accessibility_post_spec.js

@@ -201,7 +201,7 @@ describe('Verify Accessibility Support in Post', () => {
                 cy.focused().tab();
 
                 // * Verify focus is on the post text
-                cy.get(`#postMessageText_${postId}`).should('be.focused').and('have.attr', 'aria-readonly', 'true');
+                cy.get(`#postMessageText_${postId}`).should('be.focused');
             });
         });
     });
@@ -231,7 +231,7 @@ describe('Verify Accessibility Support in Post', () => {
         cy.getLastPostId().then((postId) => {
             cy.get(`#rhsPost_${postId}`).within(() => {
                 // * Verify focus is on the post text
-                cy.get(`#rhsPostMessageText_${postId}`).should('be.focused').and('have.attr', 'aria-readonly', 'true');
+                cy.get(`#rhsPostMessageText_${postId}`).should('be.focused');
                 cy.focused().tab({shift: true});
 
                 // * Verify focus is on the more button