fix(e2e): several tests (#24539)

e2e-tests/cypress/tests/integration/channels/messaging/ctrl_cmd_k_find_gm_by_matching_name_spec.js

@@ -42,6 +42,7 @@ describe('Messaging', () => {
         cy.apiCreateGroupChannel([firstUser.id, secondUser.id, thirdUser.id]).then(({channel}) => {
             // # Visit the newly created group message
             cy.visit(`/${testTeam.name}/channels/${channel.name}`);
+            cy.postMessage('hello');
 
             // # Go to off-topic
             cy.get('#sidebarItem_off-topic').click();

e2e-tests/cypress/tests/integration/channels/messaging/message_with_gif_spec.js

@@ -36,11 +36,11 @@ describe('Show GIF images properly', () => {
         cy.url().should('include', offtopiclink);
 
         // # Post tenor GIF
-        cy.postMessage('https://c.tenor.com/Ztva2YFROSkAAAAi/duck-searching.gif');
+        cy.postMessage('https://media.tenor.com/yCFHzEvKa9MAAAAi/hello.gif');
 
         cy.getLastPostId().as('postId').then((postId) => {
             // * Validate image size
-            cy.get(`#post_${postId}`).find('.attachment__image').should('have.css', 'width', '137px');
+            cy.get(`#post_${postId}`).find('.attachment__image').should('have.css', 'width', '189px');
         });
 
         // # Post giphy GIF