resolve a few other issues

Author: GreatBahram

src/shecan/api.py

@@ -29,7 +29,7 @@ def reset() -> None:
     conf.delete()
 
 
-def list_dns():
+def list_dns() -> list[str]:
     """Return a list of DNS objects."""
     with ShecanConfig() as conf:
         ips = conf.list_dns()

src/shecan/db.py

@@ -2,6 +2,7 @@
 
 from configparser import ConfigParser
 from pathlib import Path
+from typing import Self
 
 DB_PATH = Path("~/.dns_db.cfg").expanduser()
 
@@ -25,7 +26,7 @@ def _read_config(self) -> None:
         self._initialize()
         self._parser.read(self.config_file)
 
-    def __enter__(self):
+    def __enter__(self) -> Self:
         self._read_config()
         return self
 
@@ -37,7 +38,7 @@ def update(self, ips: list) -> None:
         """Store all Shecan's ip addresses."""
         self._parser[self._name]["dns-ips"] = ",".join(ips)
 
-    def list_dns(self):
+    def list_dns(self) -> list[str]:
         """Return list of Shecan's dns servers."""
         try:
             ips = self._parser[self._name]["dns-ips"].split(",")