cypress: add reason to skipped tests (#28083)

Author: mshima

generators/cypress/templates/src/test/javascript/cypress/e2e/entity/_entity_.cy.ts.ejs

@@ -275,6 +275,7 @@ describe('<%= entityClass %> e2e test', () => {
 
 <%_ } _%>
 <%_ if (!readOnly) { _%>
+      <% if (skipCreateTest) { %>// Reason: cannot create a required entity with relationship with required relationships.<% } %>
       it<%= skipCreateTest %>('last delete button click should delete instance of <%= entityClass %>', () => {
   <%_ if (clientFrameworkReact) { _%>
         cy.intercept('GET', '/<%= baseApi + entityApiUrl %>/*').as('dialogDeleteRequest');
@@ -308,6 +309,7 @@ describe('<%= entityClass %> e2e test', () => {
       cy.getEntityCreateUpdateHeading('<%= entityClass %>');
     });
 
+    <% if (skipCreateTest) { %>// Reason: cannot create a required entity with relationship with required relationships.<% } %>
     it<%= skipCreateTest %>('should create an instance of <%= entityClass %>', () => {
   <%_ fields.filter(field => (!field.id || !field.autoGenerate) && !field.hidden && !field.readonly).forEach((field) => {
     const fieldName = field.fieldName;