LDAP bind works without full DN

### Describe the bug

I was testing an LDAP outpost and forgot the OU that was used so I just bound with `cn=rgingras,dc=example,dc=com` (rgingras is my username) expecting it to fail and to go look up the OU but to my suprise it worked. I saw my user's DN was supposed to be cn=rgingras,ou=users,dc=example,dc=com but I decided to try some other designations to see what would work. All of the following did:
1. cn=rgingras,dc=example,dc=com
2. cn=rgingras,ou=rgingras,dc=example,dc=com
3. cn=rgingras,dc=ldap,dc=example,dc=com

### How to reproduce

1. Create a LDAP provider and application with base dc=example,dc=com
2. Create an outpost bound to that application
3. ldapsearch -H ldaps://outpost.example.com -x -W -b dc=example,dc=com -D cn=username,dc=example,dc=com

### Expected behavior

Binding to the LDAP outpost should require the example DN of the entity attempting the bind.

### Screenshots

_No response_

### Additional context

_No response_

### Deployment Method

Docker

### Version

2026.8.0

### Relevant log output

```shell

```