[EDR Workflows][E2E] Unskip artifacts FTR (#182787)

closes #180493

I've noticed locally that the modal where we input the blocklist entries
can sometimes get rerendered without any apparent reason. So, I've added
a retry mechanism that, in case the input's value is not present,
attempts to fill it out again.

Failure example:

https://buildkite.com/elastic/kibana-on-merge/builds/43629#018ed329-76ee-4512-aef6-5583b2cf830e


Flaky test runner:
x25 -
https://buildkite.com/elastic/kibana-flaky-test-suite-runner/builds/5871
x75 -
https://buildkite.com/elastic/kibana-flaky-test-suite-runner/builds/5873

x-pack/test/security_solution_endpoint/apps/integrations/artifact_entries_list.ts

@@ -54,7 +54,7 @@ export default ({ getPageObjects, getService }: FtrProviderContext) => {
 
   describe('For each artifact list under management', function () {
     // It's flaky only in Serverless
-    targetTags(this, ['@ess', '@skipInServerless']);
+    targetTags(this, ['@ess', '@serverless']);
 
     this.timeout(60_000 * 5);
     let indexedData: IndexedHostsAndAlertsResponse;
@@ -155,10 +155,13 @@ export default ({ getPageObjects, getService }: FtrProviderContext) => {
         } else if (formAction.type === 'click') {
           await testSubjects.click(formAction.selector);
         } else if (formAction.type === 'input') {
-          await testSubjects.setValue(
-            formAction.selector,
-            (formAction.value || '') + (suffix ? suffix : '')
-          );
+          const newValue = (formAction.value || '') + (suffix ? suffix : '');
+          await testSubjects.setValue(formAction.selector, newValue);
+          await testSubjects.getAttribute(formAction.selector, 'value').then((value) => {
+            if (value !== newValue) {
+              return testSubjects.setValue(formAction.selector, newValue);
+            }
+          });
         } else if (formAction.type === 'clear') {
           await (
             await (await testSubjects.find(formAction.selector)).findByCssSelector('button')