thick mode connect isn't honoring TNS_ADMIN or using ldap connection

1. What versions are you using?

platform.platform: macOS-15.0-arm64-arm-64bit
sys.maxsize > 2**32: True
platform.python_version: 3.12.6
oracledb.version: 2.4.1

2. Is it an error or a hang or a crash?

Error

3. What error(s) or behavior you are seeing?

When trying to connect to a database I'm getting the following error:

$ env | grep -E 'ORA|TNS|PATH'
TNS_ADMIN=/opt/oracle
PATH=/opt/oracle/instantclient_23_3:...
INFOPATH=/opt/homebrew/share/info:
ORACLE_HOME=/opt/oracle/instantclient_23_3

$ python test.py
Traceback (most recent call last):
File "/Users/slords/test.py", line 8, in
c=oracledb.connect(user=user, password=password, dsn=dsn)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/slords/.venv/lib/python3.12/site-packages/oracledb/connection.py", line 1169, in connect
return conn_class(dsn=dsn, pool=pool, params=params, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/slords/.venv/lib/python3.12/site-packages/oracledb/connection.py", line 554, in init
impl.connect(params_impl, pool_impl)
File "src/oracledb/impl/thick/connection.pyx", line 494, in oracledb.thick_impl.ThickConnImpl.connect
File "src/oracledb/impl/thick/utils.pyx", line 446, in oracledb.thick_impl._raise_from_info
oracledb.exceptions.DatabaseError: ORA-12154: Cannot connect to database. Could not find alias whse_dev in /opt/oracle/instantclient_23_3/network/admin/tnsnames.ora.
Help: https://docs.oracle.com/error-help/db/ora-12154/

If I run the same connect using sqlplus it connects fine to the database. I've got sqlnet.ora and ldap.ora in /opt/oracle. We don't use tnsnames.ora and that file has never existed in any of our installs.

4. Does your application call init_oracle_client()?

Yes

5. Include a runnable Python script that shows the problem.

$ cat test.py
import oracledb
oracledb.init_oracle_client(lib_dir='/opt/oracle/instantclient_23_3')

user='user'
password='pass'
dsn='ldap_alias'

c=oracledb.connect(user=user, password=password, dsn=dsn)

Start with the runnable test.py and the init_oracle_client() call, then compare how the connection uses TNS_ADMIN, sqlnet.ora, and ldap.ora with the working sqlplus setup. Reproduce the ORA-12154 error and trace the Thick-mode connection path; done means ldap_alias connects using the LDAP configuration in /opt/oracle without requiring tnsnames.ora.