[Discover] Change savedObjects from plugin to bundle dependency (#174274)

## Summary

This PR changes `savedObjects` from a plugin dependency to a bundle
dependency in Discover since we don't rely on the contract anymore, and
only use its static components. Part of the effort to deprecate the
`savedObjects` plugin.

### Checklist

- [ ] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/packages/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed
- [ ] Any UI touched in this PR is usable by keyboard only (learn more
about [keyboard accessibility](https://webaim.org/techniques/keyboard/))
- [ ] Any UI touched in this PR does not create any new axe failures
(run axe in browser:
[FF](https://addons.mozilla.org/en-US/firefox/addon/axe-devtools/),
[Chrome](https://chrome.google.com/webstore/detail/axe-web-accessibility-tes/lhdoppojpmngadmnindnejefpokejbdd?hl=en-US))
- [ ] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [ ] This renders correctly on smaller devices using a responsive
layout. (You can test this [in your
browser](https://www.browserstack.com/guide/responsive-testing-on-local-server))
- [ ] This was checked for [cross-browser
compatibility](https://www.elastic.co/support/matrix#matrix_browsers)

### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

src/plugins/discover/kibana.jsonc

@@ -17,7 +17,6 @@
       "urlForwarding",
       "navigation",
       "uiActions",
-      "savedObjects",
       "savedObjectsFinder",
       "savedObjectsManagement",
       "savedSearch",
@@ -41,7 +40,7 @@
       "globalSearch",
       "serverless"
     ],
-    "requiredBundles": ["kibanaUtils", "kibanaReact", "unifiedSearch"],
+    "requiredBundles": ["kibanaUtils", "kibanaReact", "unifiedSearch", "savedObjects"],
     "extraPublicDirs": ["common"]
   }
 }

src/plugins/discover/public/plugin.tsx

@@ -27,7 +27,6 @@ import { UrlForwardingSetup, UrlForwardingStart } from '@kbn/url-forwarding-plug
 import { HomePublicPluginSetup } from '@kbn/home-plugin/public';
 import { Start as InspectorPublicPluginStart } from '@kbn/inspector-plugin/public';
 import { DataPublicPluginSetup, DataPublicPluginStart } from '@kbn/data-plugin/public';
-import { SavedObjectsStart } from '@kbn/saved-objects-plugin/public';
 import { DEFAULT_APP_CATEGORIES } from '@kbn/core/public';
 import { UsageCollectionSetup } from '@kbn/usage-collection-plugin/public';
 import { IndexPatternFieldEditorStart } from '@kbn/data-view-field-editor-plugin/public';
@@ -185,7 +184,6 @@ export interface DiscoverStartPlugins {
   share?: SharePluginStart;
   urlForwarding: UrlForwardingStart;
   inspector: InspectorPublicPluginStart;
-  savedObjects: SavedObjectsStart;
   usageCollection?: UsageCollectionSetup;
   dataViewFieldEditor: IndexPatternFieldEditorStart;
   spaces?: SpacesPluginStart;