Fix the OIDC test

[siegfriedweber]

Description

The OIDC test fails with the following error:

2024-06-18 01:20:49,555 DEBUG: Starting new HTTPS connection (1): druid-router-default:9088
Traceback (most recent call last):
  File "/usr/local/lib/python3.12/site-packages/urllib3/connectionpool.py", line 467, in _make_request
    self._validate_conn(conn)
  File "/usr/local/lib/python3.12/site-packages/urllib3/connectionpool.py", line 1099, in _validate_conn
    conn.connect()
  File "/usr/local/lib/python3.12/site-packages/urllib3/connection.py", line 653, in connect
    sock_and_verified = _ssl_wrap_socket_and_match_hostname(
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/urllib3/connection.py", line 806, in _ssl_wrap_socket_and_match_hostname
    ssl_sock = ssl_wrap_socket(
               ^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/urllib3/util/ssl_.py", line 465, in ssl_wrap_socket
    ssl_sock = _ssl_wrap_socket_impl(sock, context, tls_in_tls, server_hostname)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/urllib3/util/ssl_.py", line 509, in _ssl_wrap_socket_impl
    return ssl_context.wrap_socket(sock, server_hostname=server_hostname)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/ssl.py", line 455, in wrap_socket
    return self.sslsocket_class._create(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/ssl.py", line 1042, in _create
    self.do_handshake()
  File "/usr/local/lib/python3.12/ssl.py", line 1320, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: Hostname mismatch, certificate is not valid for 'druid-router-default'. (_ssl.c:1000)

The problem is that the certificate contains the fully-qualified service names (druid-router-default.NAMESPACE.svc.cluster.local and druid-router-default-0.druid-router-default.NAMESPACE.svc.cluster.local) but not the single hostname.

In prior test runs, this issue also existed but it was ignored:

2024-06-15 00:48:36,963 DEBUG: Starting new HTTPS connection (1): druid-router-default:9088
/usr/local/lib/python3.12/site-packages/urllib3/connectionpool.py:1103: InsecureRequestWarning: Unverified HTTPS request is being made to host 'druid-router-default'. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#tls-warnings
  warnings.warn(

This pull request fixes this issue by using the fully-qualified service name.

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [x] Integration tests passed (for non trivial changes)

# Reviewer
- [ ] Code contains useful comments
- [ ] Code contains useful logging statements
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated. Follows the [style guide](https://docs.stackable.tech/home/nightly/contributor/docs-style-guide).
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added
- [ ] [Roadmap](https://github.com/orgs/stackabletech/projects/25/views/1) has been updated

[siegfriedweber]

✅ https://ci.stackable.tech/view/02%20Operator%20Tests%20(custom)/job/druid-operator-it-custom/150/

[labrenbe]

lgtm