fix: notification endpoint Dropdown width to extend all the way (#4346)

Author: ChitlangeSahas

cypress/e2e/shared/notificationRules.test.ts

@@ -218,11 +218,9 @@ describe('NotificationRules', () => {
 
     cy.get<SlackNotificationEndpoint>('@selectedEndpoint').then(({id}) => {
       cy.getByTestID(`endpoint--dropdown-item ${id}`).click()
-      cy.getByTestID('endpoint--dropdown--button')
-        .within(() => {
-          cy.contains(name2)
-        })
-        .click()
+      cy.getByTestID('endpoint--dropdown--button').within(() => {
+        cy.contains(name2)
+      })
     })
 
     const message = `

src/notifications/rules/components/RuleEndpointDropdown.tsx

@@ -61,12 +61,7 @@ const RuleEndpointDropdown: FC<Props> = ({
   )
 
   return (
-    <Dropdown
-      button={button}
-      menu={menu}
-      style={{width: '160px'}}
-      testID="endpoint-change--dropdown"
-    />
+    <Dropdown button={button} menu={menu} testID="endpoint-change--dropdown" />
   )
 }