[index management] Remove unfreeze index test since the api is deprec…

…ated and freezing is unavailable (elastic#198746)

## Summary

Remove the `unfreeze` test since the api is deprecated and its
essentially a noop.

More info -
https://www.elastic.co/guide/en/elasticsearch/reference/current/unfreeze-index-api.html

x-pack/test/api_integration/apis/management/index_management/indices.ts

@@ -22,7 +22,6 @@ export default function ({ getService }: FtrProviderContext) {
     flushIndex,
     refreshIndex,
     forceMerge,
-    unfreeze,
     list,
     reload,
     clearCache,
@@ -151,20 +150,6 @@ export default function ({ getService }: FtrProviderContext) {
       });
     });
 
-    describe('unfreeze', () => {
-      it('should unfreeze an index', async () => {
-        const index = await createIndex();
-
-        // Even if the index is already unfrozen, calling the unfreeze api
-        // will have no effect on it and will return a 200.
-        await unfreeze(index).expect(200);
-        const {
-          body: [cat2],
-        } = await catIndex(index, 'sth');
-        expect(cat2.sth).to.be('false');
-      });
-    });
-
     describe('list', function () {
       it('should list all the indices with the expected properties and data enrichers', async function () {
         // Create an index that we can assert against

x-pack/test/api_integration/apis/management/index_management/lib/indices.api.ts

@@ -40,8 +40,6 @@ export function indicesApi(getService: FtrProviderContext['getService']) {
   const forceMerge = (index: string, args?: { maxNumSegments: number }) =>
     executeActionOnIndices({ index, urlParam: 'forcemerge', args });
 
-  const unfreeze = (index: string) => executeActionOnIndices({ index, urlParam: 'unfreeze' });
-
   const clearCache = (index: string) => executeActionOnIndices({ index, urlParam: 'clear_cache' });
 
   const list = () => supertest.get(`${API_BASE_PATH}/indices`);
@@ -56,7 +54,6 @@ export function indicesApi(getService: FtrProviderContext['getService']) {
     flushIndex,
     refreshIndex,
     forceMerge,
-    unfreeze,
     list,
     reload,
     clearCache,