refactor: simplify authentication process

Renamed `pantalaimon_first_login.py` to `get_access_token.py` to clarify its purpose for new developers. Removed dependency on `pantalaimon`, streamlining the project setup and reducing complexity. This change necessitates manual configuration for secure connections but simplifies the overall authentication flow. Also, deleted the example config file `pantalaimon.example.conf`, reinforcing the move away from Pantalaimon. This shifts the focus towards direct authentication methods, potentially improving future maintainability and ease of use.

# No specific issue references
```

```
refactor: streamline authentication by removing Pantalaimon

Renamed `pantalaimon_first_login.py` to `get_access_token.py` to make its purpose clear, especially for newcomers. This shift underscores our initiative to simplify the authentication process, directly aligning with our goal for a cleaner and less complex setup. By removing Pantalaimon dependencies, we not only reduce project complexity but also embrace a more straightforward authentication method. This decision involves moving away from automated secure connections provided by Pantalaimon, requiring manual configuration but ultimately leading to a leaner codebase and potentially enhancing maintainability and usability for developers.

pantalaimon.example.conf

@@ -1,5 +0,0 @@
-[Homeserver]
-Homeserver = https://example.com
-ListenAddress = localhost
-ListenPort = 8010
-IgnoreVerification = True

pyproject.toml

@@ -30,7 +30,6 @@ classifiers = [
 
 dependencies = [
     "matrix-nio",
-    "pantalaimon",
     "setuptools",
     "markdown2",
     ]

reportbot-pantalaimon.service

@@ -1,15 +0,0 @@
-[Unit]
-Description=Pantalaimon for ReportBot
-Requires=network.target
-
-[Service]
-Type=simple
-User=reportbot
-Group=reportbot
-WorkingDirectory=/opt/reportbot
-ExecStart=/opt/reportbot/venv/bin/python3 -um pantalaimon.main -c pantalaimon.conf
-Restart=always
-RestartSec=10
-
-[Install]
-WantedBy=multi-user.target