[Search] Remove references to keyfile secret in snippets and tests (#581)

# Summary
With the changes in #527 mongot no longer requires access to the replica
set's keyfile. This cleans up tests and doc snippets that are still
referencing it.

## Proof of Work

<!-- Enter your proof that it works here.-->

## Checklist

- [ ] Have you linked a jira ticket and/or is the ticket in the title?
- [x] Have you checked whether your jira ticket required DOCSP changes?
- [x] Have you added changelog file?
    - use `skip-changelog` label if not needed
- refer to [Changelog files and Release
Notes](https://github.com/mongodb/mongodb-kubernetes/blob/master/CONTRIBUTING.md#changelog-files-and-release-notes)
section in CONTRIBUTING.md for more details

Author: fealebenpae

docker/mongodb-kubernetes-tests/tests/search/search_community_external_mongod_basic.py

@@ -71,7 +71,6 @@ def mdbs(namespace: str, mdbc: MongoDBCommunity) -> MongoDBSearch:
         "source": {
             "external": {
                 "hostAndPorts": seeds,
-                "keyfileSecretRef": {"name": f"{mdbc.name}-keyfile", "key": "keyfile"},
             },
             "passwordSecretRef": {"name": f"{MDBC_RESOURCE_NAME}-{MONGOT_USER_NAME}-password", "key": "password"},
             "username": MONGOT_USER_NAME,

docker/mongodb-kubernetes-tests/tests/search/search_community_external_mongod_tls.py

@@ -137,7 +137,6 @@ def test_create_search_resource(mdbs: MongoDBSearch, mdbc: MongoDBCommunity):
     mdbs["spec"]["source"] = {
         "external": {
             "hostAndPorts": seeds,
-            "keyfileSecretRef": {"name": f"{mdbc.name}-keyfile"},
             "tls": {
                 "ca": {"name": f"{mdbc.name}-ca"},
             },

docs/search/04-search-external-mongod/code_snippets/04_0318_create_external_keyfile_secret.sh

@@ -10,9 +10,6 @@ spec:
         - ${MDB_EXTERNAL_HOST_0}
         - ${MDB_EXTERNAL_HOST_1}
         - ${MDB_EXTERNAL_HOST_2}
-      keyfileSecretRef:
-        name: ${MDB_EXTERNAL_KEYFILE_SECRET_NAME}
-        key: keyfile
     username: search-sync-source
     passwordSecretRef:
       name: ${MDB_RESOURCE_NAME}-search-sync-source-password

docs/search/04-search-external-mongod/code_snippets/04_0320_create_mongodb_search_resource.sh

@@ -17,13 +17,6 @@ export MDB_EXTERNAL_HOST_0="mdbc-rs-0.mdbc-rs-svc.${MDB_NS}.svc.cluster.local:27
 export MDB_EXTERNAL_HOST_1="mdbc-rs-1.mdbc-rs-svc.${MDB_NS}.svc.cluster.local:27017"
 export MDB_EXTERNAL_HOST_2="mdbc-rs-2.mdbc-rs-svc.${MDB_NS}.svc.cluster.local:27017"
 
-# REPLACE with your external MongoDB keyfile secret name
-export MDB_EXTERNAL_KEYFILE_SECRET_NAME="mdbc-rs-keyfile"
-
-# REPLACE with the actual keyfile content from your external MongoDB replica set
-# For testing, this will be automatically generated by the MongoDB Community resource
-export MDB_EXTERNAL_KEYFILE_CONTENT="your-mongodb-keyfile-content-CHANGE-ME"
-
 # REPLACE with your actual external MongoDB replica set name
 export MDB_EXTERNAL_REPLICA_SET_NAME="mdbc-rs"