Doc: k8s_raw_module fixing typo K8S_AUTH_HOST -> K8S_AUTH_KEY_FILE (#46947)

The current doc of k8s_raw_module contain a copy paste of the env var name :

```
host   :
Provide a URL for accessing the API. Can also be specified via K8S_AUTH_HOST environment variable.
key_file  : Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_HOST environment variable.
```

lib/ansible/plugins/inventory/k8s.py

@@ -63,7 +63,7 @@ DOCUMENTATION = '''
                 environment variable.
           key_file:
               description:
-              - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_HOST
+              - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_KEY_FILE
                 environment variable.
           ssl_ca_cert:
               description:

lib/ansible/plugins/inventory/openshift.py

@@ -63,7 +63,7 @@ DOCUMENTATION = '''
                 environment variable.
           key_file:
               description:
-              - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_HOST
+              - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_KEY_FILE
                 environment variable.
           ssl_ca_cert:
               description:

lib/ansible/plugins/lookup/k8s.py

@@ -105,7 +105,7 @@ DOCUMENTATION = """
           variable.
       key_file:
         description:
-        - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_HOST environment
+        - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_KEY_FILE environment
           variable.
       ssl_ca_cert:
         description:

lib/ansible/utils/module_docs_fragments/k8s_auth_options.py

@@ -52,7 +52,7 @@ options:
       variable.
   key_file:
     description:
-    - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_HOST environment
+    - Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_KEY_FILE environment
       variable.
   ssl_ca_cert:
     description: