Discover - Unmapped fields seems to be cached

[P1llus]

Stack Version
Stack Version: 8.78

Browser version:
Chrome: Version 112.0.5615.138

Browser OS version:
Windows 11

Original install method (e.g. download page, yum, from source, etc.):
elastic-package (integration development tooling)

Describe the bug:

In the left side of Discover, there is a list of fields, like "available fields", "unmapped fields" etc.

If a new field mapping is introduced in a index/datastream while your current Kibana session is live, and you do not do a hard refresh (CMD + Shift + R) then Kibana still thinks the newly introduced field is an unmapped field, not allowing you to use it for visualizations or in KQL queries, even though the field itself is corretly mapped on the index template.

Steps to reproduce:

1. Spin up a fresh 8.7.1 version of the stack.
2. Enable an integration + some datastream.
3. Browse around in Discover.
4. Enable another datastream (This updates the datastream field mapping and rolls it over).
5. View discover again, new fields introduced is shown as unmapped until a hard refresh

Expected behavior:

The list of unmapped fields should not be cached, but rather retrived once the page is revisited later.

Screenshots (if relevant):

Provide logs and/or server output (if relevant):

Output from api/index_patterns/_fields_for_wildcard?

{"name":"rpc.cred.machinename","type":"string","esTypes":["keyword"],"searchable":true,"aggregatable":true,"readFromDocValues":true,"metadata_field":false}

Index mapping from GET /logs-network_traffic.nfs-default/_mapping

"rpc": {
          "properties": {
            "auth_flavor": {
              "type": "keyword",
              "ignore_above": 1024
            },
            "cred": {
              "properties": {
                "gid": {
                  "type": "long"
                },
                "gids": {
                  "type": "long"
                },
                "machinename": {
                  "type": "keyword",
                  "ignore_above": 1024
                },
                "stamp": {
                  "type": "long"
                },
                "uid": {
                  "type": "long"
                }
              }
            },
            "status": {
              "type": "keyword",
              "ignore_above": 1024
            },
            "xid": {
              "type": "keyword",
              "ignore_above": 1024
            }
          }
        },

Any additional context:

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)

[jughosta]

Probably due to the fact that data view fields are not fetched on each search request.
Similar issue #149093