Fix Cypress flakes in `dashboard/dashboard.cy.spec.js` file (#13703)

* Fix flakes in `revisions screen` block

* Improve test assertions (there were some rendering problems, so I adjusted the assertions)

frontend/test/metabase/scenarios/dashboard/dashboard.cy.spec.js

@@ -13,8 +13,7 @@ function saveDashboard() {
   cy.findByText("You're editing this dashboard.").should("not.exist");
 }
 
-// [quarantine] flaky
-describe.skip("scenarios > dashboard", () => {
+describe("scenarios > dashboard", () => {
   beforeEach(() => {
     restore();
     signInAsAdmin();
@@ -191,19 +190,26 @@ describe.skip("scenarios > dashboard", () => {
       cy.get(".Icon-ellipsis").click();
       cy.findByText("Revision history").click();
 
-      cy.findByText("What");
-      cy.findByText("First revision.");
+      cy.get(".Modal").within(() => {
+        cy.get(".LoadingSpinner").should("not.exist");
+      });
+
+      cy.findAllByText("Bobby Tables");
+      cy.contains(/revert/i);
 
       cy.get(".Modal .Icon-close").click();
-      cy.findByText("First revision.").should("not.exist");
+      cy.findAllByText("Bobby Tables").should("not.exist");
     });
 
     it("should open with url", () => {
       cy.visit("/dashboard/1/history");
+      cy.get(".Modal").within(() => {
+        cy.get(".LoadingSpinner").should("not.exist");
+        cy.findByText("Revision history");
+      });
 
-      cy.findByText("Revision history");
-      cy.findByText("What");
-      cy.findByText("First revision.");
+      cy.findAllByText("Bobby Tables");
+      cy.contains(/revert/i);
     });
   });
 });