remove typing-extensions from dependencies and upgrade to python vers…

…ion >=3.8

aeromet_py/reports/models/base/flight_rules.py

@@ -1,6 +1,6 @@
 from typing import Dict, List, Optional
 
-from typing_extensions import Protocol
+from typing import Protocol
 
 from .cloud import CloudList
 

aeromet_py/reports/models/base/string_attribute.py

@@ -1,6 +1,6 @@
 from typing import Any
 
-from typing_extensions import Protocol
+from typing import Protocol
 
 
 class HasConcatenateStringProntocol(Protocol):

aeromet_py/reports/models/metar/should_be_cavok.py

@@ -1,4 +1,4 @@
-from typing_extensions import Protocol
+from typing import Protocol
 
 from ..base import GroupList
 from .cloud import CloudList
@@ -25,7 +25,8 @@ class ShouldBeCavokMixin(HasPrevailingCloudsWeatherProtocol):
 
     def should_be_cavok(self) -> bool:
         """Analyses the conditions for CAVOK in the report. Returns `True` if CAVOK should
-        be reported, `False` if not or if there is no data to make a complete analysis."""
+        be reported, `False` if not or if there is no data to make a complete analysis.
+        """
         if len(self.weathers) > 0:
             return False
 

aeromet_py/reports/models/taf/valid.py

@@ -3,7 +3,7 @@
 from datetime import datetime, timedelta
 from typing import Any, Dict, Optional
 
-from typing_extensions import Protocol
+from typing import Protocol
 
 from ..base import Group, HasConcatenateStringProntocol, Time